Citric acid

Citric acid, of chemical formula C6H8O7, is a weak acid that occurs naturally in citruses such as lemons or oranges.

It is a natural preservative/conservative and is also used to add a mild sour taste to foods and soft drinks; it is presumably for this reason that tartaric acid is one of the ingredients of Lima Lush, a Muggle brand of fizzy drink.

Appearances

 * Harry Potter and the Deathly Hallows: Part 1
 * Harry Potter Limited Edition