Résumé
This master’s thesis relates a five-month internship at Château La Tour Carnet, “Grand Cru Classé” from the Haut-Medoc region. It presents the organization of the company, its viticultural practices (and collection of grape varieties), its wine-making methods and on-site experimental testing. The alcoholic fermentation and malolactic fermentation are key steps in the wine-making process. Implantation of the yeasts Saccharomyces cerevisiae and bacteria Oenococcus oeni, respectively responsible for these fermentations, is a major issue each year. On previous vintages, sluggish and stuck fermentations have been observed at Château La Tour Carnet. A doubt is emitted concerning the execution of the protocol of yeast rehydration. Has a result, trials on the use of a bioreactor are setup. The bioreactor and its working principle are studied to grow Saccharomyces cerevisiae and Oenococcus oeni. A comparative study is made with the usual inoculation process.