Wine cellar temperature fluctuation – Ask Decanter

Concerned about fluctuating temperatures in your wine cellar...?

Wine cellar temperature fluctuation – Ask Decanter

Alistair Macrow, by email, asks: Four years ago, I had a cellar built beneath my existing cellar, to age my wine naturally in the right conditions, but I am now concerned by fluctuations in temperature.

In the middle of winter it drops as low as 8°C; by mid-August it will climb to 16°C. This occurs slowly, maybe half a degree per week: should I be concerned?

I have installed sensors in the cellar and have been alarmed to find a difference of three or four degrees from top to bottom of the cellar.

Sebastian Riley-Smith, managing director of wine storage specialist Smith & Taylor, responds: The accepted ideal of 13°C in the cellar seems to have arisen through regional custom and the desire to enjoy well-stored wine, rather than through scientific study.

Fluctuation is not so easy, as it involves issues of range and speed. We know that a steady 10°C-15°C is acceptable for wine, and that deviation from this can seriously impact ageing ability.

A wine cellared at 23°C will age (depending on the wine) on average eight times faster than at 13°C.

We know that wine exposed to excessive heat expands, the cork starts protruding and the bottle begins to leak. Conversely, when a wine cools, a vacuum forms and sucks the wine out of the cork. The ingress of oxygen into the bottle combined with changing temperatures creates a ‘pumping’ effect, which will have a negative impact on a wine’s quality.

One proposed solution to counter this is to store bottles at an angle, enabling both wine and the air bubble to be in contact with the cork.

With a fluctuation of around 10°C, chemical and enzymatic processes are accelerated many times over. But 0.5°C of room temperature change per week will not mean the wine temperature is changing at that same level.

A fluctuation of 8°C over the course of a year is a concern, even within the reasonable band of 8°C-16°C, because of the confused chemical development of the wine.

However, if your cellar contains mainly red wines, there are good grounds to believe that – due to their higher concentration and tannins – these are better constituted to counter the vagaries of cellar temperature.

This question first appeared in the November 2018 issue of Decanter magazine.

See also: 

Does heat affect drinking windows? Ask Decanter

How to choose where to store wine

How to store Champagne at home

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