Tannins are found in grape skins, seeds and stems, as well as wood vessels such as barrels. They create a mouth-coating sensation, influence wine colour and contribute to ageing potential.

The amount and type of tannins vary based on grape variety, growing conditions and winemaking choices.

Tannins can be described by their texture and maturity, and certain grapes like Cabernet Sauvignon and Nebbiolo are naturally higher in tannins. Besides wine, they are also found in tea, coffee and dark chocolate.

What are tannins?

Tannins are a type of bitter and astringent chemical compound that belongs to a larger group called polyphenols. They occur abundantly in nature, namely in the bark of many trees and in numerous leaves, legumes and fruits, including grapes.

Tannin molecules are usually much larger than those found in other types of polyphenols, and they have a unique ability to easily combine with other molecules, especially proteins, causing them to precipitate. This is the basis of leather production, in which the structure of animal hide is changed (tanned) by using various tree barks.

What do they do?

Because tannins bind with other proteins, including those in human saliva, they create a characteristic astringent, mouth-coating sensation in the mouth.

Their primary role in nature is to make unripe fruits and seeds unpalatable, thus dissuading animals from eating them when not yet ripe. Ripening changes the structure of the tannins through polymerization – increase of their overall length due to the combination of smaller molecules – and interaction with pectins (sugar compounds whose presence increases with maturation) and anthocyanins (red colouring compounds). Different harvest dates therefore mean different tannin structure and, ultimately, different tannic structure of the final wine, provided no corrections are made in the cellar.

Where do tannins in wine come from?

In wine, they come primarily from the skin, seeds and, to a lesser extent, the stems of the grapes. During alcoholic fermentation, the juice, skins and pips (and stems if the winemaker decides to do full or partial whole-cluster fermentation) macerate together. As sugar is processed and alcohol produced, colour and tannins are released into the wine. Tannins are soluble in alcohol, but not water; the longer the skins and pips macerate during and after alcoholic fermentation the more tannic the final wine will be. This is why pre-fermentation and carbonic maceration help to add colour (from anthocyanins) and flavour compounds to wine without the simultaneous addition of tannins.

This also explains why the colour of the wine somewhat correlates with the amount of tannins. Some tannins are pigment and/or precursor of pigment release – more tannins therefore contribute to deeper colouring.

White and rosé wines are fermented by excluding or minimising the contact with grape skins and tannin levels are therefore lower than in reds. However, if a white wine is fermented with extended skin and pip contact (i.e. producing a so-called orange wine) the level of tannins – colour from yellow to amber – can be significant.

Wood vessels, if used for fermentation and/or ageing, will also contribute to the tannic content of the wine. Different types of wood (oak, acacia, chestnut, etc) have different levels of tannin that leach out into the wine; the amount naturally decreases with each use of a given vessel.

All your wine questions answered in our Learn section

How to describe tannins?

Tannins can be best described through the tactile sensations they produce – think more of mouthfeel rather than aroma or flavour. It’s important to consider both their quantity and quality; whether more or less present, tannins can be very different in structure and cause very different sensations when you taste a wine.

There are two useful groups of descriptors to define tannins – according to texture and maturity.Are the tannins soft, velvety, silky? Or coarse, grainy, chalky? These are examples of textural characteristics that mirror the sensations tannins can cause in your mouth.

Regarding maturity, do they make you think of green, crunchy, unripe fruit? Or of juicy, smooth and sweet pulp? The nature of tannins is closely linked to the grapes maturation at harvest and, therefore, will mirror the nature of the wine’s fruit profile.

Another important differentiation to make is astringency vs. bitterness. Bitterness is a taste character while astringency is, as already discussed, a textural sensation. Even though tannins are not flavour compounds, they can produce a feeling of bitterness in addition to the mouth-coating grip. This is particularly true for young red and orange wines.

What grapes have high tannins?

Some grapes are naturally higher in tannins than others. Given that tannins are predominantly in the skins and seeds of the grapes, varieties with thicker skin will generally have the potential to produce wines with higher tannins. Varieties notably high in tannins include Cabernet Sauvignon, Nebbiolo, Sangiovese, Malbec, Mourvèdre/Monastrell, Syrah/Shiraz, Tannat and Tempranillo. Thinner skinned grapes – such as Pinot Noir, Gamay, Grenache – therefore produce less tannic wines.

Still, growing conditions and winemaking choices have a crucial impact on the development and extraction of tannins and on the amount that actually goes into a wine from a given variety. This accounts for the dramatic variations in a wine from a given region, produced from the same grapes in different vintages. A cooler vintage will yield grapes with less sugar and ‘greener tannins’. Diversity within the same region can be remarkable even in the same vintage. Sites at higher altitude – where grapes are exposed to more UV radiation – or extreme wind cause the grapes to thicken their skins as a natural defence.

The latter also accounts for the different expressions of the same variety hailing from different growing regions. Take for example a Barossa Shiraz vs a Rhône Syrah. The former will likely be made with riper fruit at greater alcohol potential and the tannins will, therefore, be soft, rounded and velvety. The latter’s fruit, hailing from the cooler banks of the Rhône, will not be as ripe and the tannins not as developed, for a grainier and more angular mouthfeel.

In terms of winemaking, decisions such as fermentation temperature, length of maceration (how long the juice stays in contact with the grapes’ skins), number and vigour of punch-downs or even the type of yeasts used will have an impact on the amount of tannins that are extracted from the grapes and leached into the wine.

Do tannins influence wine ageing?

There are a number of ways in which tannins impact on the way a wine evolves – not necessarily in a positive way.

The amount of wood tannins leached into the wine will increase the longer the liquid remains inside the wood vessel. Finding the sweet spot, at which the ideal wood influence has been achieved, is a complex – and extremely subjective – winemaking decision.

On the other hand, the evolution of the tannins (either from the grapes themselves or the wood) will change the structural and textural properties of the wine as it ages. Both the nature and amount of tannins will change naturally as the molecules polymerise and eventually precipitate as sediment. Once polymerised and precipitated the tannins will no longer impart any bitterness or astringency effect, while also removing some of the wine’s colour.

Nevertheless, as key structural components, the presence of tannins generally gives wine more longevity – the ‘grip’ caused by tannic astringency will make wines feel ‘fresher’ as the primary fruit aromas fade. The binding properties of tannins also help retain flavour and colour compounds longer.

What foods are high in tannins?

Tannins are mostly associated with red, dark rosé and skin-macerated white wines. But they are also easily found – and felt – in tea, coffee and dark chocolate. While present in many fruits, nuts, spices, and legumes, they occur in much lower concentrations and are therefore not as perceptible.

Taste an over-steeped black tea or an unripe peach, however, and you’ll have no trouble perceiving the characteristic astringency of tannins.

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We investigate how long different types of wine can last after opening. While white wines, rosés and sparklers may last 2-3 days in the fridge, reds could keep for more like 3-5 days in a cool, dark place. Fortified wines vary, with some lasting weeks or months, and vintage Port lasting only a few days. Sweet wines last well in the fridge for over a week.

Watch out though for those tell-tale signs of spoilage – dulled aromas, flavours and colour, and vinegary notes. We also take a look at wine preservation systems.

How long can an open bottle of wine last in the fridge?

White and rosé wine

If you’re wondering how long wine can stay drinkable after opening, a bottle of white or rosé wine should be able to keep going for two to three days if kept in the fridge and resealed with the original cork or screwcap.

Sparkling wine

Sparkling wines, such as Prosecco or Champagne, can stay fresh and will keep some fizz for a similar amount of time, but need to be properly sealed – ideally with a specific Champagne bottle stopper which hooks onto the lip of the bottle to prevent it from being forced off due to a build up of carbon dioxide in the bottle.

Champagne expert Tyson Stelzer said that many people would be surprised that an open bottle of sparkling wine will ‘still keep some fizz in the fridge for some days.’

The most reliable way of keeping them fresh is ‘to use a Champagne stopper that provides a tight seal, and to keep the bottle as cold as possible’. So don’t listen to fables about spoons in sparkling wine’s bottle-neck.

Red wine

Red wines can generally last three to five days if stored with a stopper in a cool, dark place, said UK retailer Laithwaites after publishing a study in 2017 on the amount of wine people throw away.

Some lighter styles of red wine can be enjoyed chilled, and although full-bodied reds should be served at 16-18°C, you can still extend the life of an opened bottle by storing it in a temperature-controlled wine fridge or domestic fridge. Of course, factor in time for it to warm up again before drinking.

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Fortified wine

Some fortified wines are built to last and can be kept in the kitchen fridge for several weeks once opened.

In her feature on serving and preserving sweet and fortified wines, Anne Krebiehl MW noted that ruby and reserve Port will last for a few weeks, and Tawny Port could last for up to six weeks in the fridge.

Vintage Port, however, should be drunk up within a few days.

Marsala and Madeira, by contrast, can last for months once opened due to the long exposure to oxygen during the winemaking process, as well as the high acidity present.

Sweet wine

Sweet wines will typically last well when refrigerated. ‘These wines are resilient,’ Aline Baly, co-owner of Château Coutet in Barsac, previously told Decanter. ‘That you can keep a bottle open for more than a week is a fact unknown to many.’

How do I know if a wine has gone off?

As soon as you open a bottle of wine, you expose it to oxygen and – much like an apple browning – it will affect the wine. At first this may beneft the wine, helping it to show all its fruit complexity, however after several hours or days, it reaches a tipping point where it goes from being oxygenated to oxidised.

Things to look out for include fruit aromas and flavours that have become dulled compared to when it was first opened, or a tired colour and in extreme circumstances, even a brownish hue.

Also, look out for vinegary notes, which may be the result of bacteria causing a build-up of acetic acid.

Should I buy a Coravin?

Coravin is a wine preservation system that has been adopted by wine drinkers and top drinking and dining establishments alike. Now with several models, including one specifically for sparkling wines, the company claims that a wine’s life can be extended by days to months depending on the model used.

Coravin works by using a fine, hollow needle to piece the cork and allow you to pour out wine, while simultaneously filling the empty space in the bottle with inert argon gas which forms a barrier against oxygen.

Coravin can also be used with screwcaps and synthetic corks, although you will need to ensure you purchase the screwcap accessory. You will also need to replace the argon capsules from time to time, making Coravin an investment only worth it for those with a large collection of wine they would prefer to sample by the glass than by the bottle.

Should I buy a Vacu Vin?

Vacu Vin is the classic wine preservation device, designed to extend the life of a wine once opened by pumping out the air in the bottle to form a vacuum. From experience, this does work to a limited extent, giving your wine an extra one to two days of life compared to simply replacing the original cork or screw cap. While not preserving wine for as long as Coravin, Vacu Vin has the benefit of being more affordable.

Related articles

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It’s been 450 years this year since the Aszú winemaking method in Tokaj was first mentioned in writing – back in 1571. Get to know one of the world’s great sweet wines from Hungary and its unique production method…

What is the Aszú method?

Aszú is the Hungarian word for shrivelled and botrytis-affected berries, and the resulting wine they make.

It is not known exactly how the method of selecting Aszú berries came about, but it may be in part because serfs working the vines and the land were allowed to pick Aszú berries separately and keep the money they made from them, rather than paying a share to their landlords – a right they fought tooth and nail to protect.

The Aszú grapes must be harvested laboriously one-by-one. A good picker may pick less than 10kg per day, visiting each vine four or five times. After harvest, these grapes are crushed and soaked in either grape juice, young wine or (most commonly today) fermenting must in order to extract flavours and sweetness.

What makes Aszú wines special?

This special winemaking method is a reflection of the unique climate in this part of Hungary.

The Tisza and Bodrog rivers meet in Tokaj and because their waters are slightly different temperatures, most autumn mornings see the region enveloped in fog. Afternoons are then sunny and breezy, creating the perfect environment for noble rot to develop.

The noble rot fungus punctures microscopic holes through the grape skins, and the resulting evaporation of water content shrivels the berries to raisins.

Puttonyos and the Tokaji sweetness scale

The traditional measurement of sweetness for Tokaji was based on the number of buckets, called puttony in Hungarian, of Aszú berries added to each 136L gönci barrel (a typical Hungarian barrel) . However, today the classification is based on residual sugar.

In 2013, Tokaj regulations changed significantly, removing the ‘three’ and ‘four’ Puttonyos categories.

Today, all Aszú must be the equivalent of at least five Puttonyos, measured as 120g/L of residual sugar, whilst six Puttonyos must reach at least 150g/L. In practice, producers choose to label their wine according to the style it most represents, as long as it also meets the legal minimum.

This may sound very sweet, but Aszú wines are incredibly well-balanced with vibrant acidity. This is due to a combination of the region’s complex volcanic soils, cool nights which help to retain acidity, and the unique native grape varieties.

Furmint is Tokaj’s most planted grape variety, susceptible to noble rot but always with its hallmark vivid acidity. When making Tokaji it is typically supported by Hárslevelű and Muscat to add fruitiness and fragrance.

These wines are a true labour of love, and are also some of the world’s greatest sweet wines.

Matching Tokaji Aszú with food

Five Puttonyos Tokaji is mostly about the interplay between sweetness and refreshing crispness, which means they are well-matched to pâté and light cheeses. Fruit-based desserts like apple crumble, poached pears or fruit tart go well with this style too.

Six Puttonyos Tokaji is more about gorgeously luscious sweetness, although acidity still comes into play so that the best wines are never cloying. Try matching these wines with full-flavoured blue cheeses or varying types of paté.

More ambitious chefs might try Asian-spiced savoury dishes: Peking duck with plum sauce, caramelized pork, sticky sesame tofu, or Thai red curry with pumpkin.

What are the ageing requirements for Tokaji wines?

Recent rule changes have brought the minimum ageing period for Tokaji Aszú down to two years in total, with at least 18 months in barrel, though individual producers may choose to age for longer.

Of the other sweet styles of Tokaji, Szamorodni, which is made from whole bunches of grapes with varying proportions of Aszú berries. It must be aged for 12 months, with a minimum of six months of oak ageing. Late harvest Tokaji does not have any oak ageing requirements.

The incredibly rare Tokaji Essencia, made from the syrupy free-run juice that trickles from pressed Aszú berries, usually contains more than 450g/L of residual sugar and is fermented in glass demijohns. It is occasionally served by the spoonful, and legend has it that this exceptionally sweet wine can cure many illnesses.

You might also enjoy: 

Decanter travel guide: Tokaj, Hungary

The technique

Grafting is a technique that joins the tissues of two plants together so they continue to grow as one plant.

In viticulture this technique allows grape vines to express the desirable varietal characteristics of the scion (upper part of the joined plant) in the fruits, while developing or keeping the root system of the rootstock (lower part of the joined plant).

As a method to propagate vines, grafting has been used since Ancient Roman times, although it became vitally important for the majority of wine growing regions in the world at the end of the 19th century, resulting in the majority of the vineyards we see today being planted with grafted vines.

The phylloxera cure

In the 1860s, when new botanicals were being brought from the New World to Europe, a tiny louse, later named as phylloxera, hitchhiked to Europe in live vines from America.

Since its arrival, the pest ravaged all of Europe and almost wiped out plantings of Vitis vinifera, the wine species of the genus Vitis, in this part of the world and beyond.

See also: What is phylloxera in the vineyard?

After various failed attempts to eradicate the phylloxera, scientists discovered that the domestic vines from America are naturally resistant to the insect, which feeds on the roots.

In 1881, the International Phylloxera Congress held in Bordeaux defined grafting as the most effective and economical solution to the vineyard pandemic.

Gustave Foëx, Director of École Nationale d’Agriculture de Montpellier, was among the first scientists to conduct tests on grafting cuttings of European Vitis Vinifera onto the rootstocks of American species of vines.

Initially, only larger growers were willing to and were capable of adopting these measures.

In 1882, Foëx created a small booklet giving clear instructions for small vine-growers, and thus fueled the widespread adoption of American rootstocks in Europe.

However, there were still some issues. The American rootstocks widely adopted in France were proven to be less tolerant to chalk and some growers had to move their vineyards to areas with less lime content.

These foreign vitis species also brought in a fungal disease called downy mildew, which attacks the leaves of the grape vine. Fortunately, solutions such as the ‘Bordeaux mixture (copper sulphate and slaked lime)’ were brought quickly to market as a way to control this.

The choice of rootstocks

With more advanced research into American Vitis species, scientists have now developed a range of rootstocks that are not only resistant to various pests in the soil but also have better tolerance to environmental conditions including lime content, pH and moisture levels.

The different levels of vigor in rootstocks also became an essential factor for growers to control the yields.

The rootstocks used in most vineyards nowadays are hybrids of three species.

The Vitis rupestris species are highly vigorous and have better resistance to lime content in the soil. Vitis riparia are less resistant to lime but is gives lower vigor. Vitis berlandieri is another vigorous species with great lime resistance and also good resistance to drought.

See also: Do rootstocks affect the flavour of wines?

Grafting in modern vineyards

In nurseries, with an aim to produce phylloxera-resistant seedlings, growers conduct ‘bench grafting’ to join dormant cuttings of European species (scion) and American species (rootstock) together. The work usually takes place in winter.

The ‘whip and tongue’ method is the most common bench grafting method, which involves exposing the cambium layers of both cuttings and joining them closely together.

Machines are now commonly used in nurseries to make omega-shaped (Ω) cuts on the scion and the rootstock, before fitting them together.

The grafted vines are then kept in a warm and moist environment for weeks so the callus can join the two cuttings together. Then the vine is planted into potted soil to develop into a seedling.

Growers can also conduct grafting to an existing vine plant. This is a process known as ‘field budding / grafting’.

‘T-budding’ and ‘chip budding’ are among the most common methods, which involves making a cut to the rootstock and slotting in the bud of the scion.

Field grafting allows producers to alter the grape variety expression of the existing vines, which already have a developed root system, without uprooting and replanting the vines. This can be an economical way of changing a whole vineyard rather than re planting.

References:

Wine and the Vine: An Historical Geography of Viticulture and the Wine Trade

By P. T. H. Unwin

The Oxford Companion to Wine

What are yeasts

Yeasts are single-cell microorganisms that are responsible for the production of the enzymes that permit fermentation; the conversion of six-carbon sugar molecules into ethyl alcohol and carbon dioxide while releasing heat.

During fermentation, yeasts also produce small amounts of volatile compounds, such as esters, aldehydes and sulphur, which can contribute to the varied aroma and flavour profiles of the finished wine.

In the world of wine, the use of yeast is commonly associated with the species of saccharomyces (‘sugar fungus’) cerevisiae, also known as brewer’s yeast because it is used to make beer and leavening bread.

Cultured vs indigenous yeasts

One of the most controversial subjects in the winemaking realm is whether to use yeasts naturally present in vineyards and wineries (ambient or ‘wild’ yeasts) or those that have been manually cultivated to serve certain winemaking needs.

Traditionally, spontaneous fermentation is a combined effect of a mixture of naturally existing yeasts.

While the indigenous Saccharomyces species is usually found on the surface of grape berries, there are also other (non-Saccharomyces) wild yeasts that are present in the environment.

Although they can also impact on the flavour and quality of the wine, they tend to give way to the brewer’s yeast when the alcohol strength in the must goes significantly higher than 5% abv, or there is sufficient level of sulphur dioxide to restrict their activities.

While there is still debate about the issue, indigenous yeasts are considered by some winemakers as part of the local terroir. They are believed by some to give a more balanced and complex flavour profile to a wine.

Decanter columnist Andrew Jefford previously cited research that found indigenous yeast can not only ‘maximise personality differences, but take each wine to a different resting point in terms of sugar conversion’.

Also read: Yeast – Call Me Dad

However, using naturally existing yeasts always presents the risk of unwanted strains – such as Brettanomyces – causing aromas and flavours that are considered undesirable by some. Equally, wild Saccharomyces yeasts can also be ineffective and unpredictable.

In order to eliminate such risks and ensure a smoother, more controlled fermentation, many modern winemaking operations choose to use one or more pre-selected yeast strains.

In an earlier Decanter article, Benjamin Lewin MW estimated that use of so-called cultured yeast in winemaking ‘ranges from 70%-90%’ worldwide.

These cultivated strains, which were originally isolated from ambient yeasts, can vary widely in their characteristics, including the aromas and flavours they promote (see below), their tolerance to the environment (e.g. sulphur dioxide levels, heat and alcohol levels) and their efficiency in converting sugar to alcohol.

Producers can thus pick-and-choose the most ideal characteristics to make their wines.

Defenders of wild fermentation argue that the use of a single, cultured yeast strain leads to somewhat artificial flavours or a lack of diversity between wines,

However, some winemakers are experimenting with blends of cultured yeasts from the more than 200 strains available in the market.

Yeasts and flavours

Yeasts ‘can colour, shape and mould the entire sensual presence of the wine’, as Jefford puts it.

‘The gooseberry aromas of Sauvignon Blanc, the lychee of Gewürztraminer, the strawberry notes of Pinot Noir – none of these are found in the grapes, but they are released or created by yeast during fermentation,’ according to Benjamin Lewin MW.

Read the full feature: Yeasts – do you know what’s flavouring your wine?

Lewin pointed out that the influence of yeasts is most evident in aromatic wines, because ‘small changes in the concentrations of key components can greatly affect varietal character’.

The banana notes of Beaujolais Nouveau, for instance, are believed to come from the increased formation of isoamyl acetate due to yeast strain 71B. The CY3079 yeast can increase the hazelnut and brioche notes of Chardonnay.

The amount of monoterpenes released by yeasts is also understood to significantly alter the expression of aromatic varieties such as Gewürztraminer and Muscat.

The gooseberry and passion fruit aromas of Sauvignon Blanc can be traced back to elements in the grapes, which are converted into sulphur-containing compounds during fermentation.

Yeasts can continue to contribute to wine flavours even after they are dead.

When left in the wine after fermentation, the dead yeast cells, or lees, start to dissolve due to the enzymes in a process called autolysis.

Also read: What are lees in wine? – Ask Decanter

This process can provide a rounder mouthfeel and richer textures to a linear base wine, while adding brioche and biscuit-like flavours.

Lees aging is widely used in producing some white wines, such as in parts of Burgundy and Muscadet. It is also crucial in making Champagne, as well as ‘traditional method’ sparkling wines more generally.

Reference: The Oxford Companion of Wine

An international team of scientists has succeeded in mapping the phylloxera genome, more than 150 years since the tiny insect clandestinely travelled from the US to Europe and set about destroying huge swathes of vineyard.

It has taken more than 70 experts from eight countries nearly a decade to crack phylloxera’s genetic code, which includes ‘the largest gene family identified in a genome to date’, according to French research agency INRAE.

Why is phylloxera so feared?

After arriving in Europe as a stowaway in the early 1860s – and perhaps slightly earlier – the phylloxera pest is thought to have destroyed half of France’s vineyard area over the next few decades.

This naturally prompted despair among winemakers, and other countries were also badly affected, both in Europe and beyond.

Winemakers began to gain the upper hand once it was discovered that phylloxera could be beaten by grafting ‘vitis vinifera’ grapevines onto resistant American rootstocks.

This is still common practice, but not everywhere in the wine world. In many cases, ungrafted vines remain vulnerable to the pest, which attacks the roots in order to feed. Phylloxera therefore remains an ongoing concern.

Chile is considered the only major wine producing country to have largely avoided infestation, although pockets of untouched areas exist elsewhere, and the insect is believed to struggle on sandy soils.

The work to map the phylloxera genome, published in the BMC Biology journal, also shows that it likely comes from the upper Mississippi River.

The pest entered Europe by hitching a ride on the vitis riparia species, a wild type of American vine, according to the new research.

It is now hoped that unlocking phylloxera’s genome can help to improve ways of combating the insect.

INRAE said, ‘This new knowledge also serves to improve our understanding of biological invasions and their potentially disastrous consequences on agriculture and therefore on society and the economy.’

This page was originally published in 2010, but has been updated in July 2020. 

From the archive:

Is the Mission variety resistant to phylloxera?

Grapevine trunk disease: The ‘next phylloxera’

Vine diseases now top priority for French winemakers

Residual sugar (or RS) refers to the sugars left unfermented in a finished wine. It is measured by grams of sugar per litre (g/l).

The amount of residual sugar affects a wine’s sweetness and, in the EU, the RS level is linked to specific labelling terms. For example, a wine containing more than 45 g/l is a ‘sweet wine’.

It’s rare for a wine to drop below 1 g/l, because some types of sugar simply cannot be consumed by the yeast.

On the other hand, at least 150g/l of residual sugar is required for a ‘six puttonyos’ Tokaji sweet wine.

And, while it isn’t the fashion today, some Champagnes from the 19th century have been found to contain 150g/l of residual sugar.

These days, labelling terms for still wines in the EU include:

Up to 4g/l Dry / Sec

4 g/l – 12 g/l Medium dry / demi-sec

12 g/l – 45 g/l Medium (Medium sweet)

More than 45 g/l Sweet / Doux

For sparkling wines, the labelling terms are regulated as follows:

Up to 3 g/l Brut Nature

Up to 6 g/l Extra Brut

Up to 12 g/l Brut

12 g/l–17 g/l Extra Dry / Extra Sec

17 g/l –32 g/l Dry / Sec

32 g/l –50 g/l Demi-sec

More than 50 g/l Sweet / Doux

What’s the difference between Champagne and Prosecco?

Sweet sensation

It’s worth noting that besides residual sugar, other elements of wine could also affect people’s perception of sweetness.

For instance, high acidity gives freshness and a sense of lightness, even if the wine has a considerable amount of residual sugar.

In fact, the upper limit of residual sugar for ‘dry’ and ‘medium dry’ still wines can be raised to 9g/l and 18 g/l, if there is the appropriate level of acidity to balance.

Other factors, such as oak, fruit flavours, alcohol levels and serving temperature, can also have an impact on the perceived sweetness of a wine.

Sometimes they can trick drinkers by bringing the perception of sweetness to a wine with a very low RS level.

How can a dry wine taste sweet?

Making sweet wines

There are many reasons why extra sugars are ‘left over’ in wine without being converted into alcohol.

For example, sometimes the grape juice has such high levels of sugar that it cannot be fully turned into alcohol. This is mainly because the accumulated alcohol can eventually impede the activities of the yeast.

Typical sweet wines made using juice with a high sugar concentration include:

• Sauternes (noble rot)
• Icewine (frozen grapes)
• Late harvest sweet wines, like Recioto della Valpolicella, produced from dried grapes.

Winemakers can also choose to terminate the fermentation before the sugar has been used up.

This can be done by cooling down the ferment then filtering out the yeast, such as for Moscato d’Asti, or by adding grape spirits or sulphites to kill the yeast, such as for Ruby Port and ‘vin doux naturels’.

At a certain level, residual sugar may help a sharp, acidic wine to taste mellower and a plain wine more flavoursome.

Some everyday wines are made by simply adding sweeteners, such as preserved grape juice, to dry wines before bottling to make them more palatable.

However, residual sugar can also be a dangerous enemy to the stability of a still wine, because it may trigger re-fermentation in the bottle. Microbes may feed on the sugars left in the wine and generate unwanted flavours and gas.

Therefore, it is essential for producers to either completely eliminate the fermentable sugar in the wine, or get rid of the yeast via sterile filtration at the point of bottling.

You might also like:

What is Icewine? 

How is Tokaji sweetness measured? 

Kosher wines don’t necessarily taste any different to non-kosher wines, but they must adhere to a set of Jewish dietary laws known as ‘kashrut’ and there are also several different styles to be aware of.

The word ‘kosher’ originates from Hebrew ‘ר‎כש (kashér)’, which essentially means ‘suitable’ under the ‘kashrut’.

Wine has long played an important role in Jewish culture and tradition, and this can be seen in religious ceremonies.

‘It’s key in Sabbath dinners, and at the Passover Seder feast, participants sip from four glasses of wine,’ wrote Decanter’s Stephen Brook in a 2008 article.

What makes a wine kosher?

Interpretations vary to some extent, but to qualify as ‘kosher’ in most cases, only practising Jewish workers can handle the wine in the cellar, from crushing grapes to tasting and bottling.

Winemakers also need to be extra careful when sourcing yeasts, additives and fining agents, to make sure they are kosher, too.

Once a bottle of wine has been opened, it could cease to be kosher if handled by anyone not observant of the Sabbath.

It isn’t generally considered necessary to have the wine blessed by a rabbi, but some certification bodies may require a rabbi to supervise the production process.

Not all Israeli wines are kosher

Not all Israeli wines are kosher, but Israel is naturally the historical homeland of kosher wines and there is also evidence of vineyards being cultivated in this area going back more than 2,000 years.

In the 19th century, Jewish settlers in the Holy Land planted vineyards to replace those that had vanished under Ottoman rule. This marked the beginning of the modern wine industry in what is now Israel, said Stephen Brook.

It was then when Baron Edmond de Rothschild, son of the owner of Château Lafite, created the Carmel wine estate and started bringing in French winemaking know-how to Israel.

French varieties such as Cabernet Sauvignon, Chardonnay, Merlot and Sauvignon Blanc were also brought in at that time, and remain common varieties today.

Golan Heights Winery, which is known for its Yarden brand, has risen to international acclaim since it began producing wines in the 1980s.

Other notable names such as Ytir, Barkan, Flam and Domaine du Castel, are also playing their part in introducing Israeli and kosher wines to the world in modern times.

Do kosher wines taste different?

In most cases, not really, said US-based wine writer Howard G Goldberg in a Decanter column, back in 2009.

‘Because standard kashruth practices in the vineyard and cellar coincide with universal vineyard and cellar methods, it is relatively easy to produce high quality, competitive kosher wines in idiosyncratic and preferred standardised styles.’

However, a small percentage of kosher wines are heated as part of the production process. These wines are known as ‘mevushal’; the word literally means the wine was ‘cooked’.

After the heat treatment, the wine will remain kosher even if it comes into contact with a non-Jewish winemaker or a non-Jewish restaurant waiter or waitress serves it.

Nowadays, most mevushal wines are flash-pasteurised to 80˚C (175˚F) and immediately cooled down to 16˚C (60˚F), to minimise the impact on flavours.

In the past, wines were heated up and brought to the boil.

However, some argue that pasteurisation is not good enough for a wine to keep its kosher status.

Going international

Kosher wines are now made all over the world, from Bordeaux to California.

Goldberg said that examples of Kosher wines included Laurent-Perrier Champagne Brut NV and Châteaux Clarke in Bordeaux.

Among the various kosher certification symbols, one of the most common looks like a ‘U’ in a circle, suggesting that it’s certified by Union of Orthodox Rabbis.

A ‘K’ in a circle, a ‘K’ in a star, cRc and Hebrew ‘ר‎כש ’ are also indicators that the wine is kosher.

See also:

What is vegan wine? Ask Decanter

Corked wine at-a-glance:

How do you spot a corked wine? Look out for a damp cardboard, mouldy or wet dog smell that also dulls the fruitiness of the wine.

What causes it? TCA, also known as 2,4,6 – trichloroanisole, is the main culprit but it has other family members.

Is it bad for you? It might put a dampener on your dinner party, but cork taint is not considered harmful to health.

How common is it? That depends on who you ask, but the natural cork industry says it has significantly reduced the risks in recent years.

Can screwcap wines be ‘corked’? Technically yes, you can have ‘cork taint’ aromas because contamination can happen in the winery, but this isn’t thought to be as common.

Myth buster: This problem is not related to bits of cork floating in your wine, albeit this isn’t a strong look and may mean the cork has dried out in the bottle or wasn’t of great quality in the first place.

Where does cork taint come from?

There is a grey area about exactly what constitutes a fault in wine; you’ll find widely divergent opinions on brettanomyces, for example.

But cork taint, commonly known as ‘corked wine’, is one of the ‘undeniable flaws’ as Natasha Hughes MW wrote in her Decanter article on wine flaws a few years ago.

A potent compound with the catchy title of 2,4,6 – trichloroanisole (TCA) was identified as the main culprit of cork taint by researchers writing in the Journal of Agricultural and Food Chemistry in 1982.

They conducted tests on European red and white wines and found that even tiny quantities of TCA could spoil your wine enjoyment.

TCA is part of a group of compounds known as haloanisoles and it can be formed following a reaction between plant phenols, mould and chlorine.

Cleaning products containing chlorine were considered a major problem in both the cork industry and in the winery, but efforts have been made to reduce this source of contamination. Using chlorine to help make corks is banned, according to Apcor, the Portuguese cork association.

However, studies have shown that TCA can also form on tree bark, prior to cork production, and can also contaminate equipment in the winery.

Other compounds in the same family have been associated with cork taint-like aromas in wine, albeit less frequently.

Among them, TBA – or 2,4,6-tribromoanisole – has been traced to preservatives used to treat wood in the winery, for example. Again, wineries have changed processes to help avoid the problem.

How to spot a corked wine

Does your wine smell like a damp cardboard box or a wet dog? Has this aroma masked the fruitiness of the wine so that it’s all a bit dull on the nose?

If so, there’s a good chance that you’ve got a corked wine on your hands.

Yet it’s impossible to speak in absolute terms. Cork taint happens by degrees and some wine lovers, whether by sensory training, experience or natural sensitivity, may pick it up more easily than others.

Cork taint can sometimes cause debate among even the top experts during a tasting.

Estimates vary on how significant the issue still is. The cork industry has estimated around 1% of wines are affected, but other estimates have ranged between this and around 8%. It may partially depend on when the wine was produced.

Prevention and developments

Cork taint is very hard to spot in the winery before it’s too late, because only a small amount of contamination is needed to spoil the wine.

Prevention has been key and some top wineries, notably in Australia and New Zealand, have switched to screwcap in the last 15 years or so – citing cork taint as a motive.

But, the cork industry says it has invested heavily to reduce the problem.

Among the most recent developments, natural cork producer Amorim launched new technology that it said would improve its ability to check for TCA on its own production lines.

Amorim said the technology, known as NDtech and officially launched in 2016, allowed it to deliver corks with a ‘non-detectable TCA guarantee’.

Cork producer Diam also offers a guarantee on its stoppers, by using what it describes as a patented ‘de-aromatisation’ process, as examined by Decanter columnist Andrew Jefford in 2014.

See also: The cork comeback – published in 2017

Why is it in your wine, and is it a bad thing?

What is volatile acidity? Ask Decanter

Volatile acidity is made from compounds in types of acid found in wine, showing an aroma, rather than found on the palate.

‘In simple terms, it refers to the acidic elements of a wine that are gaseous, rather than liquid, and therefore can be sensed as a smell,’ said Julia Sewell, Assistant Head Sommelier at Hide in Mayfair and a judge for the Decanter World Wine Awards.

‘The major compound responsible for this aroma is acetic acid, which is more commonly known as vinegar. A secondary compound that is formed at the same time is ethyl acetate, which smells more like nail polish remover or paint thinner.’

Why is it in my wine?

‘It is generally wines made in older barrels or more oxidative environments that show VA,’ said Sewell.

That is because it is easier for the bacteria to thrive in less sterile conditions.

‘Sweet wines made using botrytis cinerea (noble rot) are often quite high in volatile acidity levels, as the grapes tend to have high levels of acetic acid bacteria naturally present. The same can be said of wines made from dried grapes.,’ said Sewell.

‘Wines that commonly show higher levels of volatile acidity include Sauternes, Amarone della Valpolicella and Port.’

Is volatile acidity a bad thing?

‘Although the presence of high amounts of VA is considered undesirable, in some cases a touch of volatility is no bad thing,’ said Natasha Hughes MW in her guide to wine ‘flaws’.

‘It’s an important characteristic in many wines that adds complexity and interest; often, in a positive manner, it can be described as adding ‘a lifted character’ to the aromas of the wine,’ said Sewell.

‘However, where it is not intentionally included in the wine, it is most definitely a fault, and can be an indicator of unclean winemaking.’

‘At extreme levels, VA can be quite affronting, in much the same way as vinegar or nail-polish remover can be if smelled too strongly, and ultimately the aromas can overtake a wine if it is not robust enough to balance.’

See more wine questions answered here.

What kind of flavours does it produce in a wine...?

Carbonic maceration is a form of whole bunch fermentation, when whole bunches of uncrushed grapes are used in fermentation of red wines.

It is most commonly associated with the Gamay grape and Beaujolais wines, although not exclusively.

Some key flavours associated with carbonic maceration would be:

• Bubble gum
• Kirsch
• Banana
• Strawberry

How it works

Whole bunches of grapes are placed in vats, which are then sealed and filled with CO2 to remove the oxygen.

This triggers a process within the grapes known as intracellular fermentation. Once alcohol levels reach around 2% abv, the grape skins split and release their juice.

Carbonic maceration extracts some colour from the grapes but little tannin, generally creating red wines that are light in colour, low in tannin and which have a soft, fruity wines character.

Wines made in this style include Beaujolais Nouveau and are often best when drunk young and sometimes even lightly chilled.

According to Decanter’s tasting notes decoded, ‘In these processes, esters such as ethyl cinnamate are produced in higher quantities than normal, lending flavours such as raspberry, strawberry, and bubblegum.’

What is semi-carbonic maceration?

Semi-carbonic maceration is a similar method of production, but does not include filling the vats with CO2.

Instead, when the vat is filled with the whole bunches, the weight of the grapes on the top crushes the ones below, releasing the juice. Yeast ferments the fruit and releases CO2, kick-starting carbonic maceration in the remaining un-burst grapes.

Some winemakers use this method to obtain a fresher fruit character in their wines.

Both of these methods only create a small amount of alcohol, so once it is completed, the grapes are pressed off the skins and yeast completes the fermentation process.

Whole bunch fermentation

It isn’t just Beaujolais producers who have been re-exploring this method. Pinot growers in Australia and Burgundy, for example, are also proponents of fermenting at least a portion of their vintage using whole bunches.

However, ‘Beaujolais can certainly claim to be the spiritual home of whole-bunch fermentation,’ said Simon Woolf in the February 2017 issue of Decanter magazine.

See also: The new faces of Beaujolais – exclusive to Decanter Premium members

More wine questions answered here.

What are tasters referring to when they assess tannins? And why are they important?

What are tannins? – ask Decanter

Tannins are a group of compounds found naturally in grape skins. They can also be found in black tea and traces in some berries.

They contribute importantly to the structure and ageing potential of red wines.

‘They may be flavourless and odourless, but tannins are one of the key constituents in red wine,’ said Matt Walls, regional chair for the Rhône at the DWWA.

‘In grapes, these compounds are found primarily in the skins, seeds and stems, so they tend to be more prevalent in reds.’

See also: Tasting notes decoded

Structure and texture

‘Tannins are responsible for providing red wine with most of its texture and physical impact in the mouth – more specifically, they produce feelings of astringency and bitterness, which can be pleasing in small amounts,’ said Walls.

‘Over time, tannins can change in the way they feel, often becoming softer and less astringent – this is one of the key reasons wines we age certain types of wines before drinking them.’

When tasting wine, you will often feel the presence of tannins on the gums of your teeth.

See also: What is the tannin scale? – ask Decanter

Tasting en primeur

Decanter’s Bordeaux correspondent Jane Anson notes that when tasting wines en primeur, you are looking for ‘the amount of tannin in the wine, for structure’, alongside other elements such as acidity and fruit – which will indicate the quality and ageing potential of a wine.

When tasting young wines en primeur, the tannins will feel quite harsh and prominent, as they have not had time to age and soften over time.

See more wine questions here

A significant amount of New World wine is now bottled at its destination, a trend that supermarkets have helped to drive in the UK. But what effect, if any, does this have on the wine? Barry Dick MW tells Decanter a bit more about the process.

Ask Decanter: New World wines bottled in Europe? Does it have an impact on the wine?

John Lavis, from Bishop Auckland, asks: I’ve noticed a number of southern hemisphere wines – usually at the budget end of the market – bottled in Europe.

Is it shipped in tankers as ready-made wine – and if so, what effect does this have on the wine? An example is Marks & Spencer’s Craft3 Marlborough Sauvignon Blanc which is ‘imported and bottled by Paul Sapin, La Chapelle de Guinchay, France’. Is this a hi-tech industrial business or someone’s garage?

The back label is also rather vague about the process of ‘creating exceptional Kiwi Sauvignon Blancs’. At what point can it not be labelled Marlborough, New Zealand?

Barry Dick MW, for Decanter, replies:

Today many wines from the New World are shipped in 24,000-litre Flexitank containers and bottled in their destination market.

‘There is little evidence to support an increase or decrease in quality between wines bottled at origin or destination.’

A Flexitank is like a giant bag-in-box held inside a standard freight container. On arrival in markets like the UK or Europe, the wine is bottled in purpose-built bottling sites. This practice has increased exponentially over the past 10 years, mainly for reasons of cost and environmental savings.

The impact on the wine of using this method is the interruption of the traditional winemaking process which would bottle the wine as close as possible to its origin.

There is little evidence to support an increase or decrease in quality between wines bottled at origin or destination. The handling of the wine is certainly greater, however, and more filtration occurs. By contrast, bulk shipment provides potential quality savings, as 24,000 litres of wine is transported under excellent thermal stability. On long journeys and routes over the equator, this is a serious benefit.

Sapin is a reputable business and I can attest to a highly proficient, modern bottling site.

Marlborough is one of the global regions which permits its producers to take advantage of the cost and environmental benefits of bulk shipping and packing in foreign markets while keeping the wine’s origin as Marlborough. Many other appellations, particularly in the Old World, do not permit this practice.

Barry Dick MW is a wine consultant with experience in bulk shipment and bottling in market of sale.

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

A wine's 'weight' is a tricky tasting term that can be hard to define and assess. Expert wine taster, Michael Schuster, gives us an explanation...

Determining a wine’s weight – ask Decanter

Sylvia Jiang, via email, asks: I’m doing my WSET Diploma and am unsure how to assess the weight of a wine on my palate. I think I’m confusing it with fruit intensity and alcohol. Do you have any tips?

Michael Schuster, for Decanter, replies: I’m not surprised you are confused. One’s impression of weight in wine relates precisely to both alcohol and to intensity or concentration of flavour, and it is often not easy to separate the two. Strictly speaking, weight relates to the presence of alcohol, for which you would tend to use words describing the varying degrees of body in a wine: light-bodied, medium-bodied, full-bodied, weighty, and so on. German kabinett or spätlese are light, at 7.5%-8.5% alcohol, Châteauneuf-du-Pape is full bodied at (today) 14.5% to 15.5% or more.

• How to read wine tasting notes

It is easy to discern this different weight in the mouth by tasting wines at different levels of alcohol next to each other, and noticing the different presence of alcohol alone, as it feels in your mouth. But it is easy to see why the notion of weight can be confusing when you consider that you can have wines that are full bodied, 14% or more in alcohol, and therefore quite weighty on the palate, but which don’t have much fruit or flavour concentration (many Provence rosés, for example). While on the other hand, you can have wines that are light in alcohol (7%-8%), and therefore relatively ‘gentle’ in their presence on the palate, but which have considerable concentration of flavour: for example German auslese or beerenauslese.

• How to understand wine

As you can see it isn’t simple, and it probably relates as much to semantics as to perception. So I shouldn’t fret about it overly!

Michael Schuster is an expert wine taster who runs courses for beginners to Masters of Wine students.

• Quiz: Could you be an award winning sommelier?

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

More questions answered:

Mystery wine fault – ask Decanter

Faults in wines are not always easy to define. We asked Rob MacCulloch MW to explain us a little more

Credit: WikiCommons/Narek75

How to tell if a wine is warm or cool climate – ask Decanter

Is is possible to tell whether a wine is warm or cool climate from a blind tasting? Terry Kandylis, Head

How to understand phenolic ripeness – ask Decanter

What exactly is phenolic? Justin Howard-Sneyd MW answers that question for Decanter.

High alcohol wines – ask Decanter

Do higher alcohol levels in wines impact on cellaring potential and drinking windows?

Why is there no red Champagne when two out of the three Champagne grapes are black? Peter Liem gives Decanter an answer.

John Butterwick, Boston Spa, West Yorkshire asks: Can you explain why, when two of the three Champagne grapes are black, there is no red Champagne?

Peter Liem, for Decanter, replies: The fact that there is no red Champagne is probably due to historical tastes. In the late-17th and early-18th centuries, when sparkling wines first began to be produced in the Champagne region, the best wines were valued not for their power but for their brilliance, limpidity, subtlety and finesse. Great effort was made to produce wines of increasing delicacy and refinement. Dom Pérignon, for example, almost certainly did not invent sparkling Champagne, but one of his notable achievements was perfecting the production of white wine from black grapes, making a more elegant wine.

• Roederer to make ‘Coteaux Champenois’ red wine from 2015 vintage

When sparkling Champagne began to be produced in earnest, it was definitely a white wine. Wine made from white grapes in cool areas would have a greater tendency to sparkle, and from a practical standpoint, a light-bodied, low-alcohol wine would produce a sparkle gentle enough that it would break fewer bottles. Sparkling Champagne became fashionable for its joyous and refreshing character, and in some circles it was regarded as healthier and more digestible than red wine, which was accused of causing gout. Probably, too, it was a way for the Champenois to easily differentiate their wines from those of Burgundy, its great rival in the wine world.

Today, the idea prevails that Champagne should be an elegant, lively and relatively delicate wine – red wine would be unsuitable as a base due to its body, alcohol and tannin. Some rosé Champagnes, such as those by Larmandier- Bernier, Leclerc- Briant or Piper-Heidsieck, have so much colour that they almost appear red, but these are extreme examples, and even then, these producers seek to extract colour with as little tannin as possible.

Peter Liem is publisher of ChampagneGuide.net.

• Test your Champagne knowledge and take the Decanter Champagne quiz

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Credit: Wavebreak Media Premium / Alamy Stock Photo

How long does wine last after opening?

Some pointers on how long your opened bottle will last...

Credit: Cath Lowe

What makes a perfect wine? – ask Decanter

Does perfection exist? Steven Spurrier explains how judges score...

Choosing a wine for cooking – ask Decanter

The cardinal rule is if you wouldn’t drink it, you shouldn’t cook with it. Fiona Beckett gives her view to

In search of lighter reds – ask Decanter

Not a big fan of big and heavy red wines. Julia Harding MW gives Decanter some advice on lighter red

Faults in wines are not always easy to determine. Rob MacCulloch MW explain Decanter a little more about faulty wines.

Ask Decanter: Mystery wine fault

Xavier Auerbach, Netherlands, asks: Occasionally I encounter bottles of red wine that have a very specific flaw – and not brett, oxidation, reduction, volatile acidity or the main recognisable faults. The nose is raw, bitter and stalky and the palate leaves an unpleasant impression of cocoa powder and pure alcohol. Recently a bottle of Sandeman 1994 Vintage Port was thus affected (a second bottle from the same case was fine). Can you explain this?

Rob MacCulloch MW, for Decanter, replies: This is unusual, but is probably due to the wine’s phenolic content degrading. Over time, changes in a wine’s phenolic matter can produce volatile aromas. Some of these aroma compounds, such as methylpyrazines, are shared with cocoa, and produce the aromas described. These aromas overpower the remaining fruit character in the wine and will make alcohol more apparent, too.

Why would only some bottles in a case be affected? Individual bottles have very slight cork inconsistencies which can create unstable conditions, causing phenolic content to change more rapidly. As this is a combination of factors, which may include just enough oxidation to kickstart a more rapid phenolic degradation, well-known wine faults like TCA or overt oxidation are not detectable.

Rob MacCulloch MW is training for a career in viticulture and oenology.

• How to understand phenolic ripeness – ask Decanter

• White Burgundy and burning match smell is ‘not a fault’ – ask Decanter

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

It's always a bit scary to put your precious wine glasses in the dishwasher. Xavier Rousset MS gives Decanter some tips on the best ones to choose...

Ask Decanter: Dishwasher safe glasses

Paul Williams, from Bolton asks: I want to buy some good sturdy wine glasses that will work in the dishwasher and will be versatile enough for red Bordeaux and white Burgundy. What would you recommend?

Xavier Rousset MS for Decanter, replies: Most of the top wine glass manufacturers have ranges and glasses which will meet your requirements.

One of my personal favourites is the Vino Grande range from Spiegelau, which is owned by Riedel. But I would also advise you to look at Lehmann (Gerard Basset range), Mikasa (Chef & Sommelier range) and Schott Zwiesel (Ivento range).

And it is perfectly okay to put them in the dishwasher – 95% of our restaurant glasses are cleaned this way. But you do need to consider how easy it will be to replace any you glasses that you may break, as you don’t want to end up with an assortment of different shapes and brands after one or two years.

The other key thing to take into account is the height of the stem and glass. Make sure any glasses you buy will fit comfortably in your dishwasher.

Xavier Rousset MS is joint owner of Texture restaurant and the 28˚-50˚ wine bars in London.

•  Read also: Farewell to Champagne flutes in 2016?

• Video: Xavier Rousset MS shows you how to clean your decanter

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

Does perfection exist in wine? Steven Spurrier explains how judges score wines during wine tastings.

Ask Decanter: What makes a perfect wine?

Marcus Locke, via email, asks: Why do none of your tasters ever give a wine top marks (100 points) when scoring, even when the tasting note is rapturous in its praise?

Steven Spurrier, for Decanter, replies: Top marks (100 out of 100 – or 20 out of 20 in the old Decanter system) represents perfection – not just a wine that receives rapturous praise, but one which is so good it cannot possibly be better. When judging sake, Japanese experts are generous with their full marks, as for them perfection is ‘the absence of faults’. Decanter tasters are usually judging wines young, so a perfect score for a wine with decades of development in front of it is very rare.

This said, I gave full marks to Château Margaux when judging Bordeaux 2009 en primeur and to Haut-Brion, Margaux, Lafite-Rothschild and Latour when judging the 2010 en primeur wines – these wines seemed to have transcended even themselves. Margaux 1985 served from magnum at the château this year also received the highest score possible.

While the sake experts look for absence of faults, I think that Decanter tasters can only award full marks when there is absence of doubt, both in the wine and in their judgement of it: a rare occurrence, but it does happen.

• Read about how judging week is organised for the Decanter World Wine Awards

Steven Spurrier is Decanter’s globetrotting consultant editor and is chair of the Decanter World Wine Awards.

• See Decanter’s full scores for Bordeaux 2015 en primeur wines

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

Biodynamic or organic wines? What's the difference and is one way better than the other? Lance Pigott answers that question for Decanter.

Ask Decanter: Biodynamic vs organic

M Raynor, Tumbridge Wells, asks: Is there an official certification for biodynamic wines? Are they much better than organic wines?

 Lance Pigott, for Decanter, replies: Biodynamic wines are generally certified by Demeter (www.biodynamic.org.uk/certification/demeter-certification/). But as they also certify a large array of vegetables, fruit, dairy and meat products, many French biodynamic vineyards also seek certification by Biodyvin (www.biodyvin.com). Both Biodyvin and Demeter have rules on growing and vinification that can be stricter than organic alone – for example, less use of copper sulphate per hectare, and the requirement for natural yeasts for fermentation. With biodynamics, the homeopathic preparations used on the compost and on the vines are key, and the vineyard must strive to be as self-sustaining as possible, with minimal external inputs. The planets’ influence on the growing season and on vineyard and winery operations is also taken into account.

Some wineries that use biodynamic methods in all or part of the vineyards aren’t certified at all. This is a personal choice. There are also those who are using, or trialling, biodynamic methods in their vineyards, who just use EU organic certification. But only a very small proportion of certified organic producers can be considered fully biodynamic.

Are biodynamic wines much better than organic wines? This is debatable, and it comes down to personal taste. Many proponents of biodynamism will say that the wines show clearer/brighter fruit and stronger terroir character. The vines and vineyards are healthier, but as for the final bottled wine, it will come down to the skill of the winemaker and vinification methods used.

Lance Pigott is the owner/director of Vintage Roots, a UK wine merchant that specialises in organic and biodynamic wines.

• Read also: Sulfites in wine: Friend or foe?

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

Go back to wine basics with Wine Folly's guide...

Decanter.com has teamed up with the publisher of Wine Folly’s book, A visual guide to the world of wine, to bring you several excerpts on understanding wine.

What is wine?

Wine is an alcoholic beverage made with fermented grapes. Technically, wine can be made with any fruit, but most wines are made with wine grapes…

• Quiz: How wine is made

Wine grapes

Wine grapes are different to table grapes. They are much smaller, they have seeds and they are also sweeter than table grapes.

• Quiz: Grape names

Grapevines

Grapevines take a year to grow grapes. The wine harvest in the northern hemisphere is August to October, and the harvest in the southern hemisphere is February – April.

Vintage wine

Vintage refers to the year when the grapes were harvested. Non-vintage (NV) wines are a blend of several harvests.

• Decanter.com vintage guides

Single varietal wine

A single varietal wine is made with one grape variety (e.g. Pinot Noir).

• See what our journalists learnt about wine on the WSET Level 2 course

Wine blend

A wine blend is made by mixing several wines together (e.g. Bordeaux blend).

Climates

A temperate climate is where grapes grow best. In North America, grapes frow from northern Mexico to southern Canada.

Regions with cooler climates make wines that taste more tart.

Regions with warmer climates make wines that taste more ripe.

Taken from Wine Folly: A visual guide to the world of wine. Buy now from Amazon UK// Amazon US.

Learn more about wine on Decanter.com

What exactly is phenolic ripeness? Justin Howard-Sneyd MW answers that question for Decanter.

Ask Decanter: Phenolic ripeness

Dominic Bennell, from Oxford, asks: What exactly is phenolic ripeness in grapes and why does this matter?

Justin Howard-Sneyd MW, for Decanter, replies: As grapes ripen, sugar levels increase, and acidity levels decrease. Fruits in the wild spread their genes by persuading animals or birds to eat their fruit; they then excrete the seeds, hopefully in a favourable spot. The fruit must taste delicious, so flavour molecules build up as the grape approaches ripeness.

Winemakers often use potential alcohol as a guide to when the grapes should be picked. But the ideal level of potential alcohol for a particular wine, say 13%, does not always correspond to either the flavour ripeness (when the grapes taste great) or phenolic ripeness. Phenols are complex molecules, including tannins, in the skins of the grape that can contribute bitter flavours. As the grape approaches ripeness, they change from green and bitter to pleasantly astringent, to soft and ripe-tasting.

If noticeably bitter flavours dominate the palate, then the wine is not considered to have achieved phenolic ripeness. If, however, the tannins of a red wine are supple and rounded, then the grapes used were phenolically ripe when picked.

Justin Howard-Sneyd MW is global wine consultant to Direct Wines and a winemaker.

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Read Decanter.com coverage of the Bordeaux 2015 vintage

• Got a question for Decanter’s experts? Email us: editor@decanter.com

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Not a big fan of big and heavy red wines. Julia Harding MW gives Decanter some advice on lighter red wines.

Ask Decanter: In search of lighter reds

Chris McGrath, from London, asks: Try as I might, I just don’t like wines with big, heavy tannins. Apart from Gamay, what other red grape varieties should I look out for?

Julia Harding MW, for Decanter, replies: The answer is not as simple as the question might suggest, because the amount and texture of the tannins in a red wine are influenced not only by the variety but also by where it is grown, when the fruit was harvested and the winemaking. For example, Grenache can be soft and juicy, or more savoury and structured.

Bearing all these caveats in mind, I’d suggest the following: Pinot Noir, Frappato, Dolcetto, Barbera, Schioppettino, Cornalin, Cinsault, Dornfelder, Sankt Laurent and Tarrango.

I’d also recommend that you befriend a good local independent wine merchant, who can guide you to specific wines rather than dealing in pitfall-ridden generalisations.

Julia Harding MW is co-author of Wine Grapes and Jancis Robinson MW’s associate palate.

• Read also: Pinot Noir from Germany tops Decanter global Pinot tasting

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

When to decant white wine – ask Decanter

Decanter consultant editor Steven Spurrier gives his opinion...

Credit: Photo by Marek Mucha on Unsplash

How many calories are there in wine? Ask Decanter

With advice on how to keep count from Beverley Blanning MW...

Storing screwcapped bottles – ask Decanter

Is it more beneficial to store screwcapped bottles lying down or upright? Peter McCombie MW gives Decanter an answer.

Yes, you can taste salt in wine – ask Decanter

Salt in wine? What are wine experts referring to?

Is it more beneficial to store screwcapped bottles lying down or upright? Peter McCombie MW gives Decanter an answer.

Ask Decanter: Storing screwcapped bottles

Harry Rouse, from Hereford, asks: I’d like to add some New Zealand Pinot Noir to my wine collection (to drink and keep) and am curious with regard to screwcaps and cellar storage. Natural corks clearly benefit from contact with the wine but is this the case with screwcaps? Is it more beneficial to store them lying down or upright?

Peter McCombie MW, for Decanter replies: While alternative closures were adopted by quality-conscious producers, initially in Australia and New Zealand, because they offered freedom from cork taint, they weren’t necessarily better than corks in all respects. Manufacturers have since tried to mimic the positive attributes of a cork closure by allowing controlled oxygen permeability to facilitate maturation.

Once I’d have said storage lying down made little difference, but with modern screwcap closures like Stelvin, there is a strong argument that storing the bottles on their side does have an advantage. Grégory Patriat, Jean-Claude Boisset’s winemaker, who bottles under natural cork and screwcap, prefers to store screwcapped bottles lying down in order to have a good exchange between liquid and the air through the seal. If you are planning on drinking any wines in the next 12 months I don’t think you will find much difference, but if cellaring for longer, then lying down is the preferred option.

Peter McCombie MW is is a New Zealand-born wine consultant, writer and public speaker.

• Read also: Eight exciting New Zealand wines to try

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

When to decant white wine – ask Decanter

Decanter consultant editor Steven Spurrier gives his opinion...

Do crémants age as well as Champagne? – Ask Decanter

Does Crémant de Bourgogne age as well as Champagne?

Here’s what is causing your wine headache – ask Decanter

You had a really good time last night but feel rough this morning? What exactly causes headaches when drinking too

Credit: Photo by Marek Mucha on Unsplash

How many calories are there in wine? Ask Decanter

With advice on how to keep count from Beverley Blanning MW...

Yes, you can taste salt in wine – ask Decanter

Salt in wine? What are wine experts referring to?

Salt in wine? Surely not! But what are wine experts referring to when using the word 'saline' in wine tasting notes? Stephen Brook answers that question for Decanter.

Ask Decanter: Yes, you can taste salt in wine – sometimes

David Baxter, from Nottingham, asks: Recently I’ve noticed the word ‘saline’ cropping up in more tasting notes. Surely wine can’t be salty. So what are your experts referring to?

Stephen Brook, for Decanter, replies: You’re right, saline has been creeping into tasting notes. But it’s not entirely without meaning. There are white wines – from Sicily, for example – that have a salty tang which may (or may not) be related to proximity to the sea.

I think of ‘saline’ as a cousin to ‘mineral’. We think we can detect mineral tones in, say, a Mosel Riesling or a Puligny-Montrachet, and that’s not entirely fanciful either.

Similarly, salinity does often seem appropriate when describing wine.

To confuse matters further, Italian tasters also refer to sapidità (sapidity), which is dictionary-defined as having a strong, pleasant flavour, but in Italian it seems to carry overtones of salinity too.

Stephen Brook is an awarded wine writer, author and judge has been a Decanter contributing editor for 19 years.

• More Ask Decanter articles

•  Read also: How to read wine tasting notes

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

White Burgundy and burning match smell is ‘not a fault’ – ask Decanter

Jasper Morris MW explains what is happening...

How to tell a dumb wine from a bottle past its best – ask Decanter

Charles Curtis MW offers his best tips...

Do crémants age as well as Champagne? – Ask Decanter

Does Crémant de Bourgogne age as well as Champagne?

Can wine get too cold? – Ask Decanter

Can wine get so cold that it actually damage the wine? Tony Aspler answers that question for Decanter

Does white wine benefit from being decanted? Decanter consultant editor Steven Spurrier gives his view.

Ask Decanter: When to decant white wine

Barbara Lorenzo, from London, asks: Which styles / ages of white wine would benefit from being decanted, and would you decant them for a shorter time than reds?

Steven Spurrier, for Decanter, replies: There are three reasons for decanting:

1. to allow the wine to breathe
2. to separate it from any deposit
3. because a decanted wine enhances the anticipation of pleasure.

White wines seldom throw a deposit, except sometimes tartaric crystals, and because they don’t have tannins the need for aeration is rarely necessary. So while the main reason is aesthetic, decanting should please the palate as much as the eye.

One problem is that white wines need ice buckets more than they do decanters, so it is mostly older whites that are decanted, where the cold temperature is less important, even for mature sweet wines which will be showing layered complexity.

The Bordelais often decant their dry whites as well as their reds; the Bugundians never decant; Hugh Johnson decants old Riesling; and a restaurant I knew in Paris always served Champagne en carafe. I would decant young and old white Rhônes and mature Alsace Rieslings, and both at the last minute.

Steven Spurrier is Decanter’s globe-trotting consultant editor.

• See our video on How to Decant red wine

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

Are you feeling a bit sore behind the eyes after a good time last night? David Bird MW explains what is probably causing that wine headache, otherwise known as a hangover.

Ask Decanter: What gives me a wine headache?

Michael Marsiglio, from London, asks:  Is it the sulfites in wine or the alcohol – or both – that gives you a headache the day after overindulging?

David Bird MW, for Decanter, replies: It could be both – or neither! Both of these substances are toxins, so should be approached with caution. Sulfur Dioxide (SO2) is dangerous in large doses but the tiny amount in wines is invaluable, giving great protection against oxidation.

There are a few unfortunate people who are extremely sensitive to the allergic effect of SO2, hence the warning that appears on all wine labels.

• Home gadget Ullo claims to remove sulfites in wine

Alcohol is also dangerous in large quantities but acts in a different way by dehydrating the cells in our bodies. This effect can be overcome by drinking plenty of water.

It is probable that the headache is caused by other low-level components like amino acids, polyphenols and other complex organic molecules that are an essential part of all wines.

David Bird MW is an analytical chemist, wine consultant and author of Understanding Wine Technology.

Read also:

• Sulfites in wine – friend or foe?

• The science of two alcohol free days per week

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

Many winemakers consider S02 essential for consistency and quality in wine, but there have been contentious moves to abandon its use. Are sulfites in wine harmful? And what are the effects on aroma and flavour of cutting back in the cellar? Simon Woolf takes a balanced view...

I have two bottles here in front of me. Both are Sauvignon Blanc 2012s made by Sepp Muster, a biodynamic grower in Austria’s southern Styria region, both sourced from his Opok vineyard. They taste very different: the first is extraordinarily alive, with concentrated citrus fruit and beguiling complexity; the second feels more muted, somehow more lemonade than lemon.

• Taste: Five no added sulfur wines to try

The difference between the two is a mere 10mg of sulfur dioxide (SO2) – or ‘sulphur dioxide’ – added after racking the second bottling. Muster isn’t just trying to prove a point – he’s one of a small but growing niche of winemakers seeking to reduce the intervention and additives used in wine production to close to zero. The spurning of SO2, typically used to prevent oxidation and keep unwanted bacteria at bay, is the final frontier in this quest. It’s regarded as lunacy by most conventional producers, and worshipped like the holy grail in natural wine circles. Why is opinion so polarised around this topic?

Are sulfites in wine harmful?

SO2 definitely has a bad rap when it comes to popular opinion. That could have a lot to do with the terse couplet ‘contains sulfites’, legally required to grace almost all bottles of wine sold in the US since 1988, and within the EU since 2005. Only those with less than 10 parts per million (PPM) are exempted, and here’s the rub – the fermentation process can produce more than that naturally, without any added SO2, meaning that even many ‘no added sulfite’ wines must display the offending words on the label.

Does this mean sulfites in wine are harmful? Probably not, at least not in the minuscule amounts found in modern wines – typically 20-200 PPM. Compare that to a handful of dried fruit, which will have been dosed with anywhere from 500-3,000 PPM. While this amount could theoretically cause an adverse reaction in an asthmatic, it’s extremely rare: sulfite intolerance reportedly affects less than 1% of the population. Sulfites are probably not responsible for your hangover either, as Andrew Waterhouse, professor of enology at UC Davis, asserts: ‘There is no medical research data showing that sulfites cause headaches.’

Given the apparent lack of health risks, why do winemakers like Muster insist on reducing their sulfite usage to a bare minimum, or even to zero? Despite its usefulness in slowing oxidation and knocking out harmful bacteria, some believe SO2 also mutes the delicate nuances that express vintage or vineyard character, as Muster proved to me so definitively in our tasting.

Purity of wine

Fellow southern Styrian winemaker Franz Strohmeier has also moved to zero-added SO2. He explains: ‘When we purchased another vineyard, I found a whole load of old bottles that the previous owners had left in the winery. We tasted them and I loved the complexity, the strangeness of the flavours in these old wines. I feel that when you don’t use sulfites, this character comes through more strongly even in young wines.’

Purity is the ultimate goal for many producers on the no-SO2 path. Alaverdi Monastery, in Georgia’s Kakheti region, simply strives to make its wine ‘good enough for God’. In the eyes of the monks, any additive, SO2 included, would render the wine impure and thus worthless. Belgian Frank Cornelissen, who has made wine on the slopes of Sicily’s Mount Etna since 2000, has the similarly straightforward goal to make ‘wine with nothing added’. His imperative isn’t spiritual, but built on the conviction that fine wine can be a totally additive-free product. Cornelissen believes that the knowledge of how to make wine without sulfites has simply been lost over time: ‘We have to re-learn these skills, which is a slow process.’

Isabelle Legeron MW agrees: ‘Growers are still learning how to make wine with no added sulfur – they only get one go at it every year! Perhaps it’s better if a grower gradually reduces the SO2 each year, rather than immediately trying to make a no-sulfur wine.’

• How to understand natural wines

Challenges of no sulfite wine

There are challenges. When sulfite inputs are forsworn, the risk of bacterial or microbial infection is vastly increased. Obsessive hygiene has to take their place – Cornelissen uses ionised air to clean his cellar. A more ‘laissez faire’ attitude is required when it comes to speed of fermentation, and the yeasts that will be involved. Conventionally, SO2 would be used to see off any wild yeasts on the bloom of the grapes, so that the winemaker can inoculate with his or her choice of laboratory yeast.

• Yeasts: Do you know what’s flavouring your wine?

Adverse effects vary in their seriousness – wines made without SO2 can have slightly wild, ‘funky’ aromas, which prompt the same love/hate reaction as a ripe/stinky cheese. ‘Mousiness’ is another matter – the curse of the ‘no-SO’ winemaker, this characteristic, feral finish is undetectable on the nose, but hangs around on the palate and can easily render a wine undrinkable. Once confused with brettanomyces, it’s now recognised as a completely separate problem.

How and why mousiness develops is still only loosely understood, as wine scientist Geoff Taylor of food and drink research company Campden BRI explains: ‘To the best of my knowledge, very little work has been done matching the taint with the compound.’ He clarifies: ‘The (lactic) bacteria can remain dormant for years and when conditions permit (sufficiently low free SO2, warmth), they will grow. And growth is slow.’ The risk is increased by poor hygiene in the winery or damaged grapes. As Taylor implies, this can cause severe bottle variation – another tricky factor to explain to wine drinkers used to more consistent, industrially made wines.

Producers working in this extreme fashion tend to be small, artisanal, and loosely allied under the ‘natural wine’ banner. There are exceptions – Stellar winery in South Africa’s Western Cape is a large-scale producer that very successfully introduced a no-SO2 range of wines to the UK’s supermarkets in 2008. No-SO winemaking has been around a lot longer – Jules Chauvet and Jacques Néauport, widely hailed as the godfathers of the natural wine movement, started experimenting in Beaujolais in the 1980s.

There’s little doubt that making wine without adding any sulfites is a high-wire act. Producers who succeed tend to be those with considerable experience. The results can be stunning in their clarity and character, but for most winemakers, the unpredictability and risks of spoilage or instability are simply too great. Keep a keen eye on those pushing the boundaries though – their wines might just surprise you.

Writer, columnist and natural wine specialist Simon Woolf won the 2015 Born Digital Award for best editorial/opinion wine writing.

Decanter.com has used the spelling ‘sulfur’, but it can also be spelt ‘sulphur’.

Anne Krebiehl MW answers questions on the best regions in Germany and how to find the wines...

Ask Decanter: The excitement surrounding German Pinot Noir

Wendy McCleave, from Wales, asks: I’ve noticed a real buzz about German Pinot Noir recently. Which are the best regions, and can you recommend a few producers who make great, reasonably priced wines?

Anne Krebiehl MW, for Decanter, replies: Yes, Spätburgunder, as Pinot Noir is called in Germany, is receiving more and more (well-deserved) attention and becoming more widely distributed in the UK and elsewhere.

You might not guess it, but Germany is the world’s third largest producer of Pinot Noir, according to the German Wine Institute.

A German Pinot Noir, Jean Stodden’s Spätburgunder Alte Reben, Ahr 2010, topped Decanter’s search for the best Pinot outside Burgundy in 2016.

Read more about German Pinot Noir and find top recommendations in the November 2017 issue of Decanter. 

Since Pinot Noir loves warm spots in cooler climates, Germany is eminently suited to growing it – and there are delicious wines in every region. Production costs and strong domestic demand spell high prices, but there are still bargains to be found.

Considering the prices of red Burgundy, even Germany’s top tier of wines, Grosse Gewächse, mostly available through fine-wine merchants, now represent good value – especially the estate rather than single-vineyard bottlings. But, in the UK, Oddbins, Tanners and Laithwaite’s all stock fine German Pinots below £20, as does The Wine Society. Marks & Spencer has a gentle Pfalz Pinot called Palataia which is a steal.

Total Wine in the US also stocks German Pinot Noir. Wherever you live, it’s always a good idea to speak to your local independent merchant.

More and more wines from young, ambitious producers who have yet to make their name are being shipped beyond Germany’s borders, which should be well in reach of a clued-up independent retailer or merchant.

• Read also: Germany’s Pinot Noir ‘godfather’ dies

Anne Krebiehl MW is a wine writer, educator, consultant and judge.

• Read more on German Pinot Noir in Decanter’s April issue. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

Does Crémant de Bourgogne age as well as Champagne? Rob MacCulloch MW explains...

Ask Decanter: Do crémants age as well as Champagne?

Stephen Baznik, from Belgium, asks: I recently found a bottle of Caves de Bailly, Crémant de Bourgogne Rosé 1989. Is it worth keeping any longer? Do crémants age as well as Champagne?

Rob MacCulloch MW, for Decanter, replies: Sadly Crémant de Bourgogne and other crémants do not age as well as Champagne.

Crémants generally have a higher pH and phenolic content than Champagne, with low levels of both being crucial for longevity in sparkling wine.

Caves de Bailly is located south of Champagne in the Auxerrois, which makes a higher pH level climatically unavoidable. Moreover, crémant grapes are not pressed as rapidly after harvest as in Champagne, where press houses are situated in the vineyards to minimise time between harvest and pressing.

This results in crémant juice being higher in phenolic content, particularly for rosé wines.

These factors, combined with the hot, dry 1989 vintage, mean that your 26-year-old crémant rosé is likely to be past its best. I’d open and try it now, with the expectations that it may be no more than an interesting historical record.

Rob MacCulloch MW is training in Germany for a career as a viticulturist and winemaker.

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

More questions answered:

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Champagne and Prosecco: What’s the difference?

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Do smaller bubbles mean better Champagne...?

It's not always easy to tell the difference between a wine that doesn't express much and a wine that will improve with time. Charles Curtis MW explains to Decanter how to distinguish between the two.

Ask Decanter: How to tell a dumb wine from a bottle past its best?

Spencer, via email, asks: How do you distinguish between a wine that is merely going through a dumb phase in its development and one that is over the hill?

Charles Curtis MW, for Decanter, replies: It is definitely possible to tell the difference between the two. Normally, one would say that a ‘dumb’ wine is not expressive – that is it has markedly less aroma, flavour and/or structure than one would expect.

Typically these wines will eventually open to reveal their secrets, but it will be necessary to wait. In my experience nothing will revive their spirits immediately: neither double decanting nor any other type of aeration nor any mechanical device will do the trick. Time is the only remedy.

Conversely, a wine that is past its best definitely has aromas, flavours and structure, but we’re not so sure we like what is being expressed.

These wines are most often marked by oxidation: first the fruit falls off, then the wine begins to have a meaty or savoury character; then this savoury aspect will intensify and the wine can show notes of strong umami aromas that some tasters describe as beef bouillon or mushroom or, more kindly, sous bois’. Sensitivity to this varies: some tasters dislike this register of aromas strongly, while those who often enjoy mature wines can be much more forgiving.

The meaty or beefy register is remarkably similar for reds and for whites, but with white wines the change is more marked because the colour darkens significantly. Here one often speaks of maderisation.

Charles Curtis MW is a wine consultant and former head of wine for Christie’s in Asia and the Americas.

• Read more about a wine’s dumb phase in this feature by Charles Curtis MW, including opinion from Steven Spurrier and Hugh Johnson.

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

Can wine get so cold that it actually damages the wine? Tony Aspler answers that question for Decanter.

Ask Decanter: Can wine get too cold?

Richard Cross, from Bicester, Oxfordshire, asks: In the cold, dry winter of 2012 we had major house renovations which led to me moving my wine cabinet into an outhouse in which electricity had not yet been connected.

I put a small thermometer in the cabinet and recorded consistent temperatures below freezing, going down to -7°C. Can these conditions spoil the wine? I’ve opened many bottles since and haven’t found any faults yet.

• Should you put ice cubes in wine?

Tony Aspler, for Decanter, replies: Before checking your wines, I’d check the accuracy of your thermometer. Wine begins to freeze at about -6°C (the higher the wine’s alcohol content, the lower the freezing point).

If ice forms in the bottle, the pressure through expansion will push the cork above the lip of the neck. In extreme cases this could break the hermetic seal, cause leakage and allow air in, which will oxidise the wine.

• How important is serving temperature? Ask Decanter

Inspect the capsules of your wines for bulging and wetness; if they look flat and dry you won’t have a problem. (Even though grapes for Canadian icewine have to be picked at -8°C, the finished wine is not impervious to freezing if temperatures are cold enough!)

Tony Aspler is is the Decanter World Wine Awards Regional Chair for Canada

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

White Burgundy and burning match smell is ‘not a fault’ – ask Decanter

Jasper Morris MW explains what is happening...

Are notes of vanilla a sign of American oak? – Ask Decanter

Is this true that vanilla notes in a wine are a sign it has been aged in American oak? Sarah

Is this true that vanilla notes in a wine are a sign it has been aged in American oak? Sarah Jane Evans gives her view to Decanter...

Ask Decanter: Hints of vanilla means American oak?

J Buckley, from Worcester, asks: People tell me that vanilla notes in a wine are a sign it has been aged in American oak. Is this true? Are there any other giveaways?

Sarah Jane Evans MW, for Decanter, replies:When I started my wine studies, I was taught that vanilla meant American oak, and cigar box French oak. As always, it’s a good deal more complicated.

Vanilla, or vanillin, is an aldehyde that is acomponent of the oak. It is more marked in US oak, but there are plenty of variables in the management, size and age of barrel that will also influence a wine’s aromas and flavour.

The US and France are the classic origins for oak, although Eastern Europe is common. The ageing of the chosen oak and its toasting develop different characters in the oak. So too does the size: a barrel of 225l will have a much stronger effect on the wine than a foudre of 1,000l or more. These classical casks are becoming fashionable again for their subtler influence on the wine. New oak barrels will have a much stronger effect, while a 600l Sherry butt is a blackened, inert cask, which gives no flavour but is ideal for steady ageing in a solera. Fermenting a wine in an oak barrel also gives a rounder texture and finish than simply ageing it in barrel. Then there’s all the oak substitutes – the chips and essences…

And there’s the influence of fashion. Rioja was once the classic European wine aged in US oak, known for its heady, sweet aromas. Today Rioja producers are using French oak or a mix of French and US. That tell-tale cherry fruit and vanilla cream charm is much less common. Not altogether a bad thing, as producers work to reflect their individual terroirs.

Sarah Jane Evans MW is is an award-winning journalist, currently vice-chairman of the Institute of Masters of Wine. She is also Regional co-Chair for Spain at the Decanter World Wine Awards.

See also:

• Cooperage: the art of oak ageing

• Jane Anson: Oak ageing holds the key to wine sweetness

• Bordeaux consultant to test oak influence on wine aroma

• Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

• Got a question for Decanter’s experts? Email us: editor@decanter.com

Have you ever noticed a burning match smell when putting your nose into a white Burgundy? Jasper Morris MW explains what is happening.

Ask Decanter: White Burgundy and burning match smell

Jamie Bateman, from Bristol, asks: On some white Burgundies and other white wines, I have come across an aroma that reminds me of a burning match. Is it a fault?

Jasper Morris MW, for Decanter, replies: Dear Jamie, this is not a fault – indeed far from it – though of course it may not be to everybody’s taste. It is partly a reaction to a period in which white wines, especially Burgundy, have not been ageing as well as they should.

One way to protect them is with sulphur, but you have to handle this carefully. Too much gives you a coarse sensation that catches in the back of the throat and blocks up your nostrils.

However, an intelligently managed use of sulphur woven into the fabric of the wine often delivers this intriguing burnt match or gunflint aroma, which I and others very much appreciate – so long as it does not interfere with the underlying fruit.

Jasper Morris MW is Burgundy director for UK merchant Berry Bros & Rudd. He is also Burgundy regional chair in the Decanter World Wine Awards.

See all of Decanter’s Burgundy en primeur reports

Read more notes and queries every month in Decanter magazine. Subscribe to the latest issue here

Got a question for Decanter’s experts? Email us: editor@decanter.com

Oak ageing is an art. The barrels a winemaker chooses have a marked effect on how the wine will taste, lending flavours that range from sweet to austere, says Margaret Rand.

Every wine has a back-story. We’re accustomed to tracing a wine’s history back to the unbroken grape, then shrinking and greening the grape on the vine to a hard speck, and then watching the flowering. Is it early? Late? Homogenous? It’s how we explain why wine tastes the way it does.

But from the moment we reach the barrel in which the wine is aged, there’s another back-story. It branches to the cooperage – to the fire that toasts the wood, to a cooper examining the grain, to the ageing of the staves in the rain and the wind, to an oak tree growing straight in a French forest. In the first story we ask, which vineyard? Which winemaker? When it comes to oak, we ask, which forest? Which cooper?

If you’re a winemaker, the second question is more vital than the first. If you’re a winemaker, all forests look alike. And yet the barrels you buy from Taransaud, say, are different to those you buy from, say, Boutes or Sylvain, and they make the wine taste different. Really extraordinarily different.

House style

A quick, simplistic summary: Taransaud barrels are reckoned by winemakers to make wine taste less seductive in youth than others, but are excellent in the long term – they’re powerful, a little austere. You might use them for your grand vin, maybe less so for your earlier-drinking second wine; Boutes might be better for that. Nadalié barrels give a certain sweetness. Sylvain is somewhere in between. Mercurey gives a lovely balance between fruit and wood. Seguin-Moreau is fairly similar to Taransaud. And that’s to name only a fraction of the coopers, and to ignore the subtlety with which coopers can adjust their barrels to suit your wine.

What you want, whether you’re buying a barrel or a suit, is something that fits. Your terroir, your blend of grapes, and what you are trying to achieve or express, is unique. Serious châteaux do not buy barrels off the peg. They invite their coopers along to taste their wines – the day I spoke to Véronique Sanders of Haut-Bailly she’d spent the morning doing just that, discussing with all seven of them her terroir and her grapes and the intricacies of her wine. ‘There were tiny differences between [the wines of] the different coopers; the differences were much greater a few years ago. There was a feeling that they all understand what we want.’

When the cooper understands the wine, he can suggest the right wood for it. The number of variables is mind-boggling. There’s the forest, which is usually linked to the sort of grain, but different parts of the same forest – and even different trees in the same part of said forest – may have very different grains. Basically, a tight grain from a slow-growing tree will give more elegance and less tannin; a more open grain from a faster-growing tree will give more tannins and less fruit aroma. Some winemakers have favourite forests as well as favourite coopers, but even here the cooper counts.

‘All coopers have access to the same forests, so barrels should be more or less the same, but they’re not’ says Benjamin Sichel of Château Angludet. Benjamin had been saying to Tonnellerie St-Martin that the wood needed to integrate better into his wine. ‘He said: “We have to try the forest of Jupilles” [near Le Mans]. I didn’t know it before, but I tried it and I always ask for it from him now. He tells me I’m his only client asking for 100% Jupilles. In our wine it integrates the complexity without overpowering the wine. But on its own it’s too much, and misses something. Barrels from Tonnellerie Taransaud complement it.’

A blend of coopers is always best, complementing not only different aspects of the same wine, but also different grape varieties from different terroirs. Eric Murisasco, technical director at JP Moueix, likes Remond and Taransaud barrels for the limestone of Château Bélair-Monange, and Demptos and Seguin- Moreau for the clay of Château Trotanoy. Three or four different coopers is probably the minimum, plus one or two new ones on trial. There doesn’t seem to be a big difference in approach between Right and Left Banks. When I asked John Kolasa if he treated the Merlot of Château Canon differently to the Cabernet Sauvignon of Rauzan-Ségla, he said: ‘It’s Merlot on the plateau of St-Emilion, with power and structure. If you want Vivaldi, it’s different to wanting Beethoven.’

Chewing on wood

Fabien Teitgen, technical director at Château Smith Haut Lafitte, goes a step further. The château has its own cooperage on site, so he chooses the wood. ‘When the wood is split open you can see the grain. And the smell is very important. You get an idea of the style of the wood from the smell. I chew it too, to feel the tannins, to see if they’re dry, and to judge the aromatics. From that I decide what to buy.’

Ageing is another variable – are the staves aged out in the open for one year, two years, three, or even longer? What happens in ageing is not only that rain washes tannins from the wood but also that enzymes develop in the wood, and those enzymes affect aromas. Camille Poupon of Tonnellerie Sylvain says: ‘Aquitaine has a maritime climate, so the ageing is faster than in, say, California. Two to three years in a maritime climate is enough to wash the tannins.’ Two years’ ageing gives a different result to three years. Again, it’s all about what suits your wine.

First you need rain, and then fire. The toast of a barrel (done by lighting a fire inside the half-finished barrel) comes in different grades: light, medium, medium+, heavy…. The heavier the toast, the more pronounced the flavours of chocolate, coffee and what the French call ‘torrefaction’ – roasted flavours – you’ll get. But you’ll also get less wood flavour. A heavier toast means less aroma and less finesse. With a lower toast you get more wine flavour but also more wood flavour. Complicated? Yes, very.

Most winemakers settle for more-or-less medium toast, but every cooper will have its own version of that. A short, hot toast will give different results to a longer, slower toast, even if both are called ‘medium’. A longer, slower toast gets further into the wood and gives more subtlety, more sweetness. ‘You get different flavours with different temperatures,’ says Véronique Dausse, general director of Château Phélan Ségur. ‘Burnt wood is not just burnt wood.’ Sichel was interested in low toast, ‘to gain more complexity. But coopers don’t like low toast because it only works on wood which is perfectly matured. And low toast integrates less well with the wine.’

We’re back to the fit. That integration of wood with wine is the nub of the matter. Sanders compares the perfect barrel to a Diane von Furstenberg wrap dress: ‘It shows off your femininity, it’s extremely comfortable and doesn’t hide anything, and it fits and flatters.’ And actually, like a dress, you can try it on and change your mind – sometimes.

Tasting samples of the same wine from different coopers after 18 months’ ageing shows just how different the results are. Taste wines after just 10 days in barrel and you can already see the direction in which they are travelling – they’re branching away from each other, some to opulence, some to structure. At Phélan Ségur, Dausse and her staff taste all the barrels when the wine has been in them for just two hours. That’s enough to tell them if the combination of wood and wine is going to work. If not, they can change the combination. It’s a fair old task, because it involves several hundred barrels; but if it’s necessary (‘We’ve done it a couple of times’) they’ll do it. With a top-quality, new French barrique costing €600-€700 (£500-£575), it’s too expensive a story to get wrong.

Written by Margaret Rand