In my nearly twenty years in the wine auction business I have come across every conceivable type of wine storage. I have been in hundreds of wine cellars on three different continents and set up three commercial wine storage facilities. It has gotten to the point where I can detect subtle differences in temperature and humidity without having to measure. I am a walking, talking, thermo-hygrometer.
Most of the collectors that I have worked with have been concerned almost to the point of obsession with maintaining their wine at as close to a perfectly constant 55 degrees Fahrenheit as can be achieved. That is a laudable goal no-doubt, but I feel that too often the other half of the wine storage equation gets overlooked. In my observation, humidity is at least as important for proper storage as temperature. Without question the best old wine collections that I have come across – the ones with the best levels, the firmest corks and the healthiest wines – have invariably come from cellars that maintain very high levels of humidity. In fact, I have grown to believe that the level of humidity in a cellar is a better predictor of the soundness of the wines therein than the temperature.
This may sound like sacrilege to many but I am less concerned with the specific temperature that a cellar maintains than I am with the consistency of the temperature over the course of the year. So long as the temperature is less than 60F and more than 50F and it does not vary more than three degrees over a twelve-month period, I am typically satisfied.
I don’t think that there is necessarily an “ideal” level of humidity. When it comes to protecting your corks – the damper the better but you can consider 65-80% to be the range for which you should shoot. The reason I consider 80% to be the upper limit is that if you get significantly above that your labels may start to peel but your corks will still love it. There is nothing like the feeling of walking into a damp, stone-walled, earthen-floored cave deep underground. The heaviness of the air as soon as I walk into the cellar is the tell-tale sign. I almost don’t even need to look at the bottles because I just know they are going to be beautiful. Of course I DO look at the bottles, the levels, the corks, the labels and everything else but sometimes you just know walking into a cellar that assessing bottle conditions is going to be a breeze. It is the density of the air that tells me that more than the coolness.
I get this feeling more with older wine cellars and cellars that are deep underground than with the newer above-grade ones. Many modern cellars try to maintain that perfect level of humidity that will keep labels pristine while also protecting the corks and they tend to err on the dry side. From my perspective this is too big a risk to take. As far as I am concerned a slightly damp-stained label and slightly corroded capsule caused by high humidly in the cellar is simply a sign of proper storage.
So if you are setting up your new wine cellar please PLEASE take my advice. Don’t skimp on the humidity.