Annex D - Advices

Codified File

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.

Characterization of wines resulting from overpressing

OIV-MA-D1-02 Characterization of wines resulting from overpressing


In view of the results of the discussions concerning the tests on DESCRIPTIVE CHARACTERISTICS OF WINES RESULTING FROM OVERPRESSING, the experts have confirmed that, for the group of tests done, the behavior of wines is very different depending on the variety. This renders immpossib1e all interpretation concerning wines coming from several varieties.

Moreover, the effects of the different methods of pressing and of vinification techniques, such as prefermentation maceration, must be taken into account.

Studies must be pursued to show wines resulting from overpressing and a definition of overpressing sought after.

Level of sodium and chlorides ions in wines

OIV-MA-D1-03 The level of soidum and chloride ions in wine


The level of Chloride and sodium ions in wines essentially depends on the geographic, geologic and climatic conditions of vine culture.

As a general rule, the levels of these ions are low.

the content of these elements is increased in wines coming from vineyards which are near the sea coast, which have brackish sub—soil or which have arid ground irrigated with salt water and the molar ratio cf Cl/Na+ therefore varies significantly and can even have a value close to one (1) which could imply the addition of salt (NaCl) to the wine.

When wine contains excess sodium (excess sodium is equal to the content of sodium ions less the content of chloride ions expressed as sodium), it is generally less than 60 mg/L, a limit which may be exceeded in exceptional cases.

The laboratories and official control agencies, confronted with elevated levels of Cl and/or Na+, must take the above conclusions into account and possib1y make inquiries to the official agencies of the country of origin before expelling these wines.