Term (also deposit, flocculate, crystallise) for the precipitation of various substances in wine in the form of flakes, crystals or similar. These include the settling of the lees during fermentation and the deposit (mainly in red wines) or tartar during bottle ageing. The latter two do not affect the quality of a wine. In contrast, there are precipitations of substances or turbidity due to wine defects. These include metals such as iron or copper, which cause the wine defect black f racture. See also under polymerisation.