Now my cellar isn’t exactly perfect; it gets warmer than I would like and more humid than I would like, but it seems to do a fine job maturing wines over the long term. So, what exactly are the perfect conditions for cellaring wine, then?
Well, the quality of one’s cellar conditions are simply determined by four criteria. Let’s take a look at each, beginning with the simplest.
Some folks might want you to believe that the world ends, but the truth is you’ll probably just end up with slightly cloudy wine, which can be rectified by standing the bottle up for a day or two before serving it!
The second criterion to judge would be light. While the damage caused by light is subtle, there is no doubt that UV rays damage wine. It’s called light shock, and it causes damage by stimulating otherwise stable organic compounds to become things they shouldn’t.
That’s the bad news; the good news is that unless you're leaving your wine out in the sun, or under intense lights, you’ve got nothing to worry about. A few hours of light will cause no damage to your wines, and this happens to be incredibly easy to control. Turn those lights off!
The next attribute of your cellar you need to look at is humidity. Most experts recommend humidity be maintained somewhere between 55% and 80%. The higher the better, right? Well in a real cellar, and by real I mean one with wine in barrels, the higher the better is right. Wine barrels are made of porous wood and the lower the humidity the greater the loss from those barrels, frequently referred to as the angel’s share!
Not only does that translate into a loss of product, and therefore money, but it opens the door for lots of bad things to happen to the wines in those barrels. Now, in your cellar you have your wine in glass bottles, sealed fairly tightly with a nice bit of tree bark, or even more tightly by glass or screwcap closure. Things are going to have to get mighty dry for a long time before things start going south on those bottles.
Now having said that I have watched the fill in bottles in cellars go from into the neck to high shoulder in the span of just a few years. That is due to low humidity and a bad or less than ideal cork. Most corks will do just fine for 10 or 20 years without being treated to tropical humidity. Remember, while one end of that cork is enjoying ambient humidity of your cellar, the other is literally being bathed in wine.
I would recommend keeping one’s cellar above about 50% humidity, but once you get past 75% or so you’ll find that your labels will start disappearing, and if you’re using pine or untreated lumber for your racking you’ll also find mold blooms and spreads among the bottles. That’s an aesthetic issue that can make for some nasty looking cellars, but it won’t hurt the wine any!
This leaves temperature as the final aspect to be examined. Here is where we get into real trouble. Not only do we have to worry about the actual temperature of the cellar, but we also should be concerned about the rate of change of temperature should our cellars not be regulated by refrigeration units. This is actually a convenient place to take a break since both the upcoming discussions of temperature control and refrigeration units are each worthy of their own article.