Definition: Synthetic yeasts

Furthermore, a large part of the yeast flora on grapes is destroyed by the synthetic fungicides used to control pests in vineyards. Yeasts selected in the laboratory can compensate for this situation. They are therefore commonly used. Not only do they ensure fermentation, but they also contribute to the aromatisation of wines. For example, yeast 71 B gives primeur wines a banana flavour. For this reason, they are called "aromatising yeasts". In order to avoid standardising the taste of wines, the future lies in selecting yeasts specific to each terroir. A wide range of yeasts already exists, affirming the distinctive character of wines from the main wine-growing regions of France.

The latest laboratory research has now made it possible to develop transgenic yeasts. These are capable of fermenting grapes and, at the same time, releasing some of the acidity in the must, with the aim of avoiding subsequent acidification. Another area of research involves incorporating the malolactic fermentation gene into alcoholic yeast to trigger both fermentations at the same time. The future will reveal the impact of these artificial interventions on wine quality. Finally, by using enzymes, it is possible to release aromas that are specific to certain grape varieties. However, both enzymes and selected yeasts increase varietal character at the expense of terroir.