Use of fumaric acid on must or during alcoholic fermentation

Fumaric acid has been approved by OIV for the use on wine in 2021. This practice consists in treating wines with fumaric acid to inhibit malolactic fermentation by controlling the growth and activity of lactic acid bacteria. Doses between 300 and 600 mg/L are recommended. Fumaric acid during fermentation is metabolized mainly into malic acid. It could be interesting to use the addition of fumaric acid for acidification by increasing the presence of malic acid (L) at the end of alcoholic fermentation and to participate in the blocking of malolactic fermentation during fermentation. Its use would reduce the risks of unwanted or too early malolactic fermentation, especially in the case of vinification without or with few sulfites. Trials were conducted by IFV in partnership with Dubernet Laboratories at pilot level, with the main grape varieties from different regions of France, and in red, white, and rosé vinification. The fumaric acid modality was compared to acidification modalities by malic acid and/or tartaric acid with additions in identical concentration in equivalent per liter (20 meq/L or 1.5 g/L expressed in tartaric acid). A test under cellar conditions (under derogation art 4 - reg N° 934/2019) was also carried out by the Dubernet laboratory in the case of vinification in carbonic maceration.