Term for the crystalline mixture of sparingly soluble salts of tartaric acid, mainly from potassium hydrogen tartrate (also potassium bitartrate) or to a small extent also calcium tartrate, which is formed by combining tartaric acid with potassium or calcium forms. Prose names are wine diamonds or wine stars. Weinstein is particularly common in wines made from overripe or late-harvested grapes, 90% of which is potassium hydrogen tartrate. It is separated out in the form of fragments of glass similar to small crystals, rods and leaves. This can already be done in the fermentation or expansion tank (raw tartar), especially with cold treatment. The crystal formation increases with increasing alcohol content, low temperature and rising PH value (from 3.2) too. Color changes or calcium clouding can also occur.
Weinstein is sparingly soluble in water and therefore settles on the tank and barrel walls, on the bottom of the bottle or on the cork. In most cases, however, this only takes place in the bottle, which is favored when stored in a cool place. The color is reddish to brown for red wine or whitish to gray-yellow for white wine. It is completely harmless to health, feels like sharp-edged sand and tastes neutral to sour. But it is not one wine faults, but it is undesirable for purely visual or aesthetic reasons. Weinstein has the advantage over the depot (where it can also be included) that it can be separated from the wine relatively easily. Due to modern filter and stabilization methods, Weinstein hardly occurs today.
Before the bottling Weinstein stability tests may be carried out by determining the saturation temperature. A simple option is the "refrigerator test", in which two sample bottles (one of which is enriched with 2 ml of alcohol = imitation of low temperature) are kept in the refrigerator for five to seven days and shaken daily. If there is no crystallization, the wine can be regarded as stable in tartar. In order to inhibit the formation of tartar metatartaric before the bottling added. The effectiveness is 12 to 36 months depending on the quality and tartar oversaturation below 20 ° Celsius.
Weinstein is precipitated (removed) by various processes. These are electrodialysis, Cold stabilization (see under beautiful ) or Contact method, Stabilization can also be achieved with the newly approved Miitel CMC respectively. Rapid tartar stabilization is only possible through lower temperatures. However, quality-conscious producers avoid cooling below minus 4 ° Celsius to protect the wine. In the Middle Ages, tartar and what was produced from it Weinstein oil used as a remedy (see under Tartarus ). A list of all wine ingredients is under total extract contain.