Vinegar

Vinegar is a sour liquid used as a condiment, or as a preservative, and obtained by the fermentation, or by the artificial oxidation, of ethanol.

Vinegar is used in an alchemical medicine, along with Salt, Urine, Sal Ammoniac and a particular Sulphur Vive.

Turning vinegar back into wine (and thus revert the fermentation/oxidation process) is part of the sixth year Charms curriculum at Hogwarts School of Witchcraft and Wizardry.

Appearances

 * Harry Potter and the Philosopher's Stone (film)
 * Harry Potter and the Half-Blood Prince