and fall to the bottom. Tannic acid (or gallotannic) C76-H52-O46 is used for the clarification of white wine, using casein, gelatin, or Isinglass. Stabilisation The majority of wine components are dissolved in the wine: certain components, however, may take an insoluble form during ageing or storage of wine – this is the case with tartaric acid. A salt containing potassium, potassium bitartrate is in the form of crystals at the bottom of the bottle. This is a natural phenomenon but many producers seek to avoid this as dealers and uninformed consumers take these crystals as a fault. It is caused or accelerated by cold storage: low temperature reduces its solubility. The habit of refreshing white wine makes this wine particularly sensitive to this phenomenon. Several solutions are available to stabilize the wine: The first is to cool the wine to a negative temperature near freezing for several weeks. The potassium bitartrate crystals precipitate and can be removed by filtration prior to packaging in bottles or bag-in-boxes. This solution is costly in refrigeration energy and can negatively affect the organoleptic qualities of the wine. Another solution is to introduce Metatartaric acid, a tartaric acid polymer, into the wine. Its mode of action is still unknown but it prevents microscopic crystals from growing. However, the effect is not sustainable in the long term (between 6 and 18 months) because it hydrolyzes when warm. A third way is electrodialysis: an electric current between two plates attracts the wine ions and eliminates them. However, this solution not only acts on tartaric acid but also other compounds especially potassium which is responsible for the formation of insoluble bitartrate and also modifies the organoleptic qualities. However, it does allow a definitive stabilization. Reports of high tartaric stability in white wines matured on lees has led to research in this area. A protein from the hydrolyzate of the yeast (mannoproteins) allows salts of tartar to keep their solubility. The addition of this compound industrially permits a good quality stabilization. This solution is the least expensive for energy and refrigeration equipment and does not alter the aromatic perception of wine. Nevertheless, tests conducted by the Cooperative Institute for Wine of Languedoc-Roussillon did not show conclusive effectiveness. Finally the study of the addition of cellulose gum or carboxymethylcellulose (CMC) conducted in recent years led to its approval in 2009 (EC Regulation 606/2009). Some producers who sell their own products