Cold-Stabilize Your Wine February 18 2015
Cold stabilizing will reduce the acidity of grape wines and is a good technique to use for some of those highly acidic local WI varietals. You can cold stabilize the wine by placing it in a cold spot (between about 28-40F) for couple weeks or months even -- so now is a great time to use an attic, garage, or basement for this purpose. These chilly temperatures cause tartaric acid to precipitate as potassium bitartrate crystals. You will see the wine will get cloudy and crystals will form on the bottom of the carboy. Wait until the sediment has settled and rack when the wine is still cold. Because the procedure works on tartaric acid, it will only work effectively on grape wines and the wine must be fermented out completely first.