Résumé
The domain André Brunel - Les Cailloux, certified HVE3, has 90 ha of vines produced under the Châteauneuf-du-Pape and Côtes du Rhône appellations. Since many years, the Vaucluse region has been affected by severe periods of drought, which results in an increase in pH, a drop in acidity, and wines with heavier and more alcoholic profiles. In another hand, consumers have an increasing tendency to drink light, fruity wines with less alcohol. They also want to consume wines with fewer inputs, said to be "more natural" and better for their health. So, the domain has found an alternative to chemical acidification of wines: acidifying yeasts. My experiment focuses on bioacidification by a commercial Lachancea thermotolerans yeast strain in sequential inoculation with an industrial Saccharomyces cerevisiae yeast. This yeast was tested on a vat of marselans and compared to a control vat fermented only by industrial Saccharomyces cerevisiae yeast. Considering the results, the experiment was unsuccessful unlike the year before when it produced too much lactic acid. Therefore, it is an alternative to be used with caution, in addition to acidification by adding tartaric acid, as it is difficult to control.