Compendium of International Methods of Wine and Must Analysis

Download document

Gluconic Acid

OIV-MA-D1-01 Gluconic acid

Gluconic acid is always present in musts and wines.

In wines derived from a sound, mature harvest, its level does not exceed 200—300 mg/L.

Gluconic acid increases through over-ripening by raisining and especially by the intervention of Botrytis cinerea.

Its presence at higher levels in wines — other than wines infected with noble rot of which gluconic acid is a characteristic constituent — cannot be considered a sign of bad quality linked to a harvest seized with gray rot, which must be demonstrated by other means. ln fact, by appropriate vinification techniques, it is possib1e to obtain wines of quality in this case.

As to fraud by addition of gluconic acid, this is not a factor to be taken into account since there is no reason for it.