DIY Custom Wine Cellar

Ideal Wine Storage Temperature and Controlling The Temperature Changes

A constant temperature is the single most important prerequisite for cellaring wines long-term.

A wine bottle left out on a wine rack in the kitchen has to face some extreme changes in temperature. On an average day the wine might be stable at, say, 24C, but in summer, the room may heat up to 30C. At the same time, the wine in the bottle is likely to warm up to at least 27C. In doing so, the liquid naturally expands, possibly even pushing the cork out slightly or causing a small amount of wine to be expelled around the cork. (This will quickly evaporate but may leave a slight residue under the capsule.) This movement has also weakened the seal of the cork. When the temperature drops again, the wine cools, contracts and may consequently draw a small amount of air into the bottle around the cork. It is here that the biggest problem lies. This can occur even if the wine does not leak past the cork. (Leakage can easily be identified by stiff capsules that resist rotation.)

Throughout the bottling procedure, the winemaker works hard to very carefully limit any contact the wine has with oxygen. Excessive contact results in oxidation, a chemical reaction that causes the wine to age prematurely, ultimately making it flat and lifeless. Colour deteriorates, aroma and fruit flavour diminish quickly and the wine may become bitter. Such avoidance of oxidation is even more important during the cellaring process. If oxygen is allowed to pass into the bottle around the cork, the quality of the wine will slowly deteriorate.

More of a problem, however, is that of rapid temperature change. Seasonal variations aside, the daily temperature variation in our house is often in the order of 10oC. This results in a fluctuation of some 2–3oC in the temperature of wine in the bottle during an average day. Such conditions will cause a wine to deteriorate rapidly.

So what is ideal? The smaller the variation, the better. Although it is difficult to pinpoint exact numerical standards, I propose that excellent results would be achieved if one could maintain a daily bottle temperature variation of less than 0.5oC, a weekly variation of less than 1oC, and a yearly variation of not more than 5oC.

Wine can actually be stored at a much higher temperature without great consequences, but the temperature changes must MUST be slow. A great money saving tip on keeping the temperature steady that I found on another website is to:

Try sticking water bottles (the type that go on water coolers), full, into the room…fill up available space. The bottles come in crates that stack. Water acts well as a temperature swing modifier. In fact, most dense things like stones, bricks, etc. will work but water may be your best bet. Plus, in case you need the water, it’ll be there…though not sure how long you can store water in those plastic bottles before it “goes”. It’s hard to find water in glass carboys these days…in fact, you can buy carboys (not expensive) and fill them with tap water (with a touch of hydrogen peroxide or unscented chlorine bleach…just a touch…added before sealing).