Résumé
This thesis, presented with a view to obtaining the National Oenology Diploma, highlights various works carried out within the framework of a four-month internship carried out within the castle Pédesclaux. The current trend is the expansion of biodynamic farming practices and the growing desire of winegrowers to make their terroir speak through the elaboration of indigenous fermentations. It is in this sense, that the technical team of the castle Pédesclaux has set up a study on the comparison of cultural routes and fermenter conduct on the profile of finished wines. This study is carried out on two plots of cabernet-sauvignon noir located in the heart of the prestigious appellation Pauillac. A monitoring of the physico-chemical and microbiological parameters during the winemaking process has been established, which is supplemented by sensory analyses of the various methods studied. These measures revealed several points about the 2021 vintage. The comparison of the cultural, biological and biodynamic routes, during a fermentation directed by LSA did not reveal any difference on fermenting kinetics or triangular discriminatory tests. Nevertheless, differences were perceived in the evolution of anthocyanin levels and sensory analysis, both in favour of the “Biodynamic Cultural Route” modality. The comparison of the fermenting lines, indigenous and LSA, did not reveal any difference on the fermenting kinetics, the evolution of phenolic compounds and reducing sugars. However, differences were obtained in microbiological analyses, triangular discriminatory tests and sensory analyses, the latter being clearly in favour of LSA-directed fermenter conduct. In view of the trend of these results for the 2021 vintage, the Château Pédesclaux can consider expanding its biodynamic cultivation practices but must nevertheless continue to develop a protocol for controlling indigenous fermentations.