Tartaric acid as decalcifier?
Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, especially grapes, but also bananas, tamarinds and citrus fruits. Its salt, potassium bitartrate, commonly known as tartaric acid, is formed naturally during the fermentation process. It is usually mixed with sodium bicarbonate and sold as a baking powder, which is used as a propellant in food preparation. The acid itself is added to food as an antioxidant E334 and to give it its distinctive acidic flavour.
Tartaric acid is an alpha-hydroxycarboxylic acid, has diprotic and aldaric acid properties and is a dihydroxy derivative of succinic acid.
Tartaric acid, as tartaric acid is also sometimes called, is contained in some types of baking powder as mentioned above, but is otherwise less well known as a household remedy. Compared to vinegar and citric acid, however, it has the advantage that it is less aggressive and can therefore also be used in coffee machines with aluminium components. You can find it in pharmacies and drugstores, but you can also buy it online.
For a concentrated solution of tartaric acid as a descaler, it is usually recommended to add two tablespoons of acid to one litre of water.