In English its more scientific names are potassium bitartrate and potassium hydrogen tartrate. In German, Weinstein is the most common name (meaning the crystals that form in wine), but you may also find Weinsteinsäure (wine crystal acid) or simply Weinsäure (wine acid).

We have not run into any German cooks who use cream of tartar, however. We have never seen it in a German grocery store, but you can purchase it in pharmacies.