Sometimes I read ads from offsite wine storage facilities who claim that even a 1 or 2 deg variation in wine temperature can be very detrimental to the long term health of the wine. They point to package cellar units, like the Vintage Keeper 220 that I have, saying that the temperature may vary 3 to 5 degrees during its on / off cycle. The inference is that using these home units is a bad decision for the health of your wine investment.
BUT, I realize that it is really the temperature of the wine that counts. Air temperature is not as important. I believe that the liquid temperature of the wine in bottle must vary far less than the air temperature. I believe that the liquid temperature must level off somewhere at the average of the air temperature.
Has anyone ever done a recorded test of this to see if my assumption is true? Has anyone recorded liquid temperature over time in a package cellar unit?