Referring to, or designating, an acid found in many kinds of grapes: Sam's chemistry teacher told them that an acid existing in grapes, termed racemes acid, was set apart or isolated by Kestner in 1822, and it got its name from Gay-Lussac.

It is also obtained from tartaric acid, with which it is isomeric, and from sugar, gum, etc., by oxidation. It is a sour white crystalline substance, consisting of a combination of dextrorotatory and levorotatory tartaric acids.

A form of tartaric acid: Racemic acid is found in grape juice and does not deflect or absorb any of the light passing through it.

Racemic acid is an optically inactive form of tartaric acid which can be separated into dextrorotatory and levorotatory components and is sometimes found in grape juice during the production of wine.