Cold stabilization removes particles from white wine.
Cold stabilization is part of the wine-making process. Its purpose is to remove tartrate crystals from the wine during its fermentation stage. Also known as "wine diamonds," the tartrate deposits are harmless, but commercial winemakers wish to prevent them so that consumers do not think they have found glass or other particles in their bottle. The removal of tartrate crystals gives the appearance of a superior product.
Potassium Bitartrate (cream of tartar)
Grpaes naturally contain both tartaric acid and potassium ions.
Tartaric acid is an organic acid normally found within a grape. Potassium and calcium ions can also be found in grapes. When tartaric acid and potassium combine they form a salt that can precipitate from the wine under cold conditions to form a compound called potassium bitartrate. Potassium bitartrate are clear crystals also used in cooking and commonly known as cream of tartar.
Process of Cold Stabilization
Cold stabilization is the process of dropping the temperature of the wine, following fermentation, for a period of 1 to 2 weeks. This forces potassium bitartrate crystals to form. The crystals will then separate from the wine and stick to the sides of the holding vessel. When the wine is removed (known as racking), the crystal deposits will remain behind. This speeds up the natural process by which potassium bitartrate would crystallize and precipitate at more moderate temperatures.
Why Only White Wine?
The process of cold stabilization is typically done only to white and rose whites. Red wines do form crystals, as all grapes contain both tartaric acid and potassium ions. However red wine is generally stored and served at room temperature which means it does not get cold enough to form crystals. Additionally any sediment present would be less noticeable in reds.
Importance of Cold Stabilization
Our first impressions of any wine are visual and greatly influence our overall enjoyment of the wine. Therefore both clarification and stabilization are important, particularly for commercial wine makers. As such, cold stabilization of wine has become standard industry practice. Some wine makers, though, argue that cold stabilization impairs the flavor and character of the wine.
Tags: acid potassium, form crystals, from wine, potassium bitartrate, tartaric acid potassium, acid potassium ions
