Cold Stabilization

Definition - What does Cold Stabilization mean?

Cold stabilization is a clarification technique which can prevent the formation of crystals in wine bottles; these are also called wine crystals or wine diamonds. Just before the process of bottling, the temperature of the wine is lowered to approximately 30 degrees Fahrenheit for up to two weeks. This triggers the tartrates and other solids to precipitate out of the solution.

After the cold stabilization process, the wine can easily be separated from the solids. If the wine crystals are not removed through the cold stabilization process, the crystals will form when the wine is stored in a refrigerator for an extended period of time. Although the wine crystals have no noted side effects, its appearance can make us think that there are pieces of broken glass present in the wine.

WineFrog explains Cold Stabilization

The tartrate crystals are formed in wine due to a supersaturation with tartaric acid. This makes the wines unable to hold more tartaric acid than they can naturally sustain. The excess tartaric acid then solidifies and forms crystals. When wines have excess tartaric acid, they are considered to be tartrate unstable and hence unpleasant to drink.

Many factors such as temperature changes, blending of wines, moving your wine around, and adding additives such as bentonite can cause the suspended acid to crystallize. Also, the higher the pH the higher the chances of crystals forming. So, to solve this problem, cold stabilization is required. It is a simple process in which the temperature of the wines should be reduced to 30 degrees (F) or less for at least 36 hours. This process will take longer if the wine is warmer than that. To help with this process, potassium bitartrate powder can be added, which is actually made up of small tartrate crystals. They act as catalysts in helping the tartaric acid to bond with them, speeding up the process of cold stabilization.