Ask Wine Wizard

Evaporation Clarification


Mark Backlund — Anacortes, Washington asks,

I was proud to see my letter was selected for publishing in your great column (October–November 2011). Unfortunately the question was misunderstood. I didn’t intend to suggest stopping “paying back the angel’s share.” In fact, continual topping off has become one of the primary tenets of my wine religion! Instead, I wanted to discuss the possibility that adding back whole wine to the barrel while evaporation took away only water (and alcohol?) wouldn’t result in a concentration of all the other constituents and therefore the flavor, and therefore be something to encourage. Wine in, water out, more wine in, more water out?

Thanks for clarifying your question a little bit. I am glad to hear you regularly top off your barrels, it’s a practice all of us need to do. Alcohol and water definitely do evaporate out of barrels (along with small amounts of other volatile aroma constituents of wine) and the resulting headspace does need to get refilled as this occurs. I find that topping monthly, usually replacing between 1⁄4 to 1 gallon every time, is enough to keep my wine sound. The given amount of wine you lose in the “angel’s share” as you refer to it above will change depending on the humidity and temperature of where you store the barrels, as well as the age and stage of your wine. I always lose more volume when my wine is very young and going through ML as it’s so gassy. The CO2 blows off and you lose volume as the wine settles down. And I lose less when the wine is sulfured and simply aging, anywhere after about four months of age. Don’t forget that you also lose volume
Response by Alison Crowe.