COLD STABILIZING reduces acid in wineses AND helps it to CLEAR.

During January and February the cool climate winemaker needs to cold stabilize his wines. Cold stabilization reduces some of the acid. If you used Potassium Bi-Carbonate to reduce the acid, cold stabilization is part of the equation and you MUST cold stabilize.

Put glycerin or sufficient alcohol (vodka) in the airlock to prevent freezing. Place the carboy at 25-30^o F for 2 weeks or more. A temperature of 25-30 degrees F is safe temperature for the amateur winemaker dealing with glass as a container. Transfer your wine to a  plastic PET jug or a primary fermentor for cold stabilizing. 

Excess tartrates will precipitate from the wine. This mellows the wine by reducing the acid. It will help stabilize the wine by preventing these tartrates from settling out after bottling. Rack into a clean carboy while still cold, adding proper metabisulfite. Top up with wine.

Filter if desired and bottle when stable.  Always rinse bottles with a metabisulfite solution. Drain well. The drainer trees are very nice for this purpose.

If your climate doesn’t allow conditions for cold stabilizing, utilize an old refrigerator. If you can find a vintage model with the icebox in the main interior, cut the bottom out of the icebox and allow that cold to drop into the refrigerator to obtain the lower temperatures. 

If you live in our northeastern winter climate and are using a garage or other outbuilding or cellar steps, install a thermometer and keep a log of outside temperatures plus the temperature of the chosen area for comparison. If the expected mean overnight is going to be “in the teens”, you’ll appreciate knowing whether your wine will safe or not. The sort-of-safe low-end temperature range is 20 degrees F.  A safer low end temperature is 25 degrees F.  You may luck out if your carboy is in an area that went to 16-20 degrees F, but do you have luck? Some winemakers have had two 5-gallon carboys of wine stabilizing side by side and had one break but not the other!

Super Seeding

Super seeding is the use of a mega dose of tartaric acid at the rate of 4 grams/liter and keeping the wine in agitation for 2-3 hours at 26^oF.  Without seeding, the cold stabilization (detartration) should be extended for a month or more rather than weeks.  (Crystals from earlier reactions can be ground up with a mortar and pestle and recycled for seeding.)