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.