Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.
Dear Dr. Vinny,
What does it mean if a wine was “cold fermented”?
—Edward, Wellington, New Zealand
One of the byproducts of fermentation, when yeast converts grape sugars to alcohol, is heat.
But if it is warm in the winery and the fermentation temperature goes unchecked, it could possibly get so warm that the yeast can die and the fermentation can get stuck. Some winemakers also believe that the flavors can start to taste cooked or stewed and less fresh with warmer fermentations. A warm, fast fermentation can also mean fewer aromatics.
There are plenty of terrific wines made with warm ferments. But other winemakers prefer a cold, slow fermentation, which they believe will help preserve color, fresh fruit flavors and aromatics. At the same time, if things get too cold, the fermentation can slow to a point of stopping and getting stuck that way. It certainly takes a lot of attention to execute a cold fermentation.