Résumé
This thesis will be presented in the context of obtaining the National Diploma of Oenologist of the faculty of pharmacy of Montpellier. Château Siran is one of the oldest in the Margaux appellation and remains an estate with a family soul. Its wines are recognized thanks to its constant search for perfection and to get the best out of its vines and grapes. It is with this in mind that the Cuvée Bordeaux Supérieur is undergoing a major change due to the decline in sales of this wine. Within this thesis, we deal with a topical subject: climate change and rising temperatures that bring heavy and too alcoholic wines. Château Siran wants a simple wine to drink with less alcohol and more freshness and fruit. Research by many institutes and laboratories are carried out in recent years to counter these problems very present in hot regions. Oenological products and especially yeasts seem to be the solution, but other options may open to us. We worked on two solutions: an early harvest and a yeast co-innoculation from the Laffort laboratory. It is two solutions have the same objective, a decrease in alcohol and a contribution of fruit and freshness by a beautiful acidity. Unfortunately, problems with climatology and winemaking did not make it possible to complete the trial. This is found during the tasting and analysis of it where few significant differences are highlighted.