The unique quality of St Emilion wines depends to a large extent on the region's various soils. And there are a lot of them. JAMES LAWTHER MW gets his hands dirty.
Country yarn, merchandiser’s dream or serious influence on wine quality? The notion of terroir is complex, sometimes puzzling and has provoked much debate over the years. Arguments for the validity of the concept are stronger when seen at close quarters, and nowhere is the view clearer than in St-Emilion. Larger than the combined area of Margaux, St-Julien, Pauillac and St-Estèphe, St-Emilion has 5,500 hectares (ha) under vine. It has various different viticultural zones, or terroirs, and corresponding styles and standards.
Seen on a general scale, viticultural terroir is best described as the effect of several influencing factors on the cultivation of the vine. Primarily, these include climate, mesoclimate, topography and soil. Also to be reckoned with is the even less predictable aspect of man’s technical expertise in exploiting these factors. St-Emilion’s climate is the temperate, oceanic version found throughout Bordeaux. Rainfall is high – around 800-900mm a year – and shows yearly variation, as does temperature (yearly average 12.8°C). Hence varieties in vintage quality. Differences within the appellation (mesoclimate) are slight and not marked enough to have a direct bearing on quality. The region is generally hilly, so aspect and exposure play a part. With a maximum altitude of only 100 metres though, slope has a limited impact and is really only of importance with regard to the evacuation of rain water. This leaves soil as the main variant.
St-Emilion has a variety of soils, all of which have a different influence on the cultivation of the vine and, ultimately, the quality and style of the wine. Some are more propitious to viticulture than others, but key to the best terroirs is the soil’s ability to restrict the vine’s water supply. This limits shoot growth in the summer, reducing berry size and stimulating the concentration of colour pigments and tannins.
‘The control of water supply is more important than mineral content, particularly in Bordeaux’s humid climate,’ explains Kees Van Leeuwen, professor at Bordeaux’s Faculté d’Oenologie and consultant to Château Cheval Blanc. ‘The soils best adapted to do this include not only gravel, but limestone and certain heavy clays, all of which are found in St-Emilion.’ Experiments undertaken at the Faculté also confirmed a difference in aromatic expression between wines from different soils.
St-Emilion has an intricate mosaic of terroirs. But for simplicity’s sake, six principal areas have been identified here. All produce different styles of St-Emilion wine, and confirm their status as great or mediocre terroirs by one indubitable fact – the ageing potential of their wines. Naturally, though, variations exist within each zone and individual estates may have vines in more than one terroir.
1. LIMESTONE PLATEAU
It is exactly that – a bedrock of limestone fashioned from fossilised marine life known in France as calcaire à astéries. It covers the centre of the region running east to west from the commune of St-Etienne-de-Lisse to the town of St-Emilion. The clay-loamy topsoil is generally thin – sometimes no more than 50cm – though there are areas of deeper red and brown clay.
Contrary to popular belief, the roots of the vine do not have to dig deep in this type of terrain, but merely descend as far as the bedrock. Here, the porous limestone rations the uptake of water, absorbing the excess volume in times of heavy rain and distributing just the right amount of liquid refreshment in dry periods. Both of St-Emilion’s principal grapes, Merlot and Cabernet Franc, thrive on this soil.
Wine from this terroir offers finesse with a more limited but quality-oriented tannin content, lithe fruit weight, cool freshness and subtle aromas that gain in complexity with age. The best need seven to eight years bottle age and are deceptively long-ageing (30 years plus).
No surprise, then, that a good percentage of St-Emilion’s premiers grands crus classés have vineyards on this terroir, the best examples being Châteaux Belair, Canon, Magdelaine, Trottevieille and Clos Fourtet. The grands crus classés include Balestard-la-Tonnelle, Cadet-Piola and Villemaurine. All are located to the west, near St-Emilion town. One or two grands crus, notably Châteaux Haut-Villet, Mangot and Pressac, benefit from a similar soil profile at the eastern end of the plateau.
2. HILLSLOPES (OR COTES)
The hillslopes around the plateau are composed of a deeper clay-limestone mix over a fine-textured, loamy clay known as Fronsadais molasse. These soils are poor but have a high water retention capacity, allowing a greater water uptake than the plateau above. The slopes to the south and west are steeper, those to the east more broken in relief. Those with a southerly or south-easterly exposure have the greater benefit of aspect.
Merlot and Cabernet Franc are again receptive to these soils. The wines have fresh fruit aromas, are more tannic and, again, long-ageing. They blend well with wines from the plateau, as evidenced by the fact that eight of the 13 premiers grands crus classés have vines in both terroirs.
Those with a strong côtes profile include Ausone, Pavie and l’Arrosée, La Clotte and Larcis-Ducasse among the grands crus classés. In the eastern sector lies part of the vineyard of Château Fombrauge (and the majority of Magrez Fombrauge), while on the southern côtes and to the north and east respectively are Fleur Cardinale and Faugères.
This terroir really consists of three separate components. At the footslopes below the town of St-Emilion lies a band of deep, sandy (siliceous) soil. The water supply here is less restricted and the terroir not as favourable as the plateau or côtes. But, with good vineyard management, successful results can be achieved.
Defining wine style here is more tricky given the various approaches to winemaking and the fact that a number of properties, like Château Angélus, have vines on the côtes as well. Also in this sector are Châteaux Canon-la-Gaffelière and Matras. Overall, ageing potential is more limited than on the côtes or plateau. There are two other areas of footslopes (pieds de côtes). North-east of St-Christophe-des-Bardes the clay and loam soils and northerly exposure provide a cooler, later ripening site. Merlot is the preferred variety for this zone and in hot, dry years can provide firm, full-bodied wines for drinking over 5-10 years. In difficult years, however, they tend to be hard and abrasive. Examples here include Châteaux La Bienfaisance and Lavallade.
South around St Etienne-de-Lisse, the better aspect ensures the harvest is usually a week earlier than in the north-east. The soils are clay and sandy silt and the wines fresher, a little less rustic and with roughly the same ageing potential. Good examples are Châteaux Jacques Blanc and Trapaud.
4. QUATERNARY GRAVEL
At the north-west limit of the appellation, bordering with Pomerol, this tiny sector principally covers two grand estates – Cheval Blanc and Figeac. Gravelly soils from the quaternary era identical to those found in the Médoc are predominant here. These soils are the predilection of Cabernet Sauvignon, providing firm, tannic wines with a complex aromatic range.
Both premiers grands crus classés have long ageing potential (30-plus years) but very different characteristics. Château Figeac benefits most from the gravel soils and with a vineyard planted between Cabernet Sauvignon, Cabernet Franc and Merlot, produces wines that are more Médocian in style. Firm but lighter bodied, tannic with a fine aromatic range, they require bottle age to evolve.
Château Cheval Blanc, with 60% Cabernet Franc and 40% Merlot, is also aromatically complex but accessible in the early years. There’s a powerful tannic structure wrapped in a smooth, almost opulent texture, the result of part of the vineyard being located on the same heavy, water-retaining clays found at Pomerol’s Château Pétrus.
5. ANCIENT SANDS
The ancient sands which cover a fair percentage of the north-west corner of the appellation are wind-blown and devoid of gravel. Water control is less efficient and the wines’ character is based more on a fine, fruity-floral aroma and delicate weight and structure. They age quickly and are best drunk at around two to five years. Typical examples are wines from the lieu-dit La Grâce Dieu – Châteaux La Grâce Dieu, La Grâce-Dieu-Les-Prieurs and Franc Grâce Dieu.
There are, however, areas within this zone where clay content is greater, offering more density and ageing potential. This is generally the case for Corbin wines, as well as at estates such as Chauvin and La Dominique.
6. ALLUVIAL DORDOGNE PLAIN
The alluvial plain between the foot slopes and the Dordogne river is poor viticulturally. The relief is flat, the land fertile, drainage poor and the water table high. It needs considerable investment and astute vineyard management to achieve high standards. But it can be done, as Gérard Perse proved at Château Monbousquet.
For those with less exhaustive means but a will to curb vine vigour and excessive yields, a lighter-framed, fruit-driven wine can be produced on these soils. Merlot is the principal grape variety, providing an early drinking wine best consumed within two to five years. Better examples include Châteaux Gaillard, Moulin Galhaud, Pontet Fumet and Val d’Or.
Amid the sandy, silty soils one gravelly vein follows the river from Vignonet to Libourne. Better drained and warmer, these recent alluvial soils offer the zone’s greatest potential. Château Quinault is located here but given the level of investment and winemaking style, it is less typical. A better example is Château Gueyrosse, which always has bright colour, attractive ripeness of fruit and a firm, balanced finish. The wine drinks well at 5-10 years.
Written by JAMES LAWTHER MW