Native yeasts are microorganisms that the winemaker can use to make wine. This process proves to be perilous, as these small mushrooms are difficult to tame, but if the producer manages to find the perfect balance, the spontaneous fermentation triggered by the yeasts can work wonders.
Focus on native yeasts
Yeasts are small, single-celled fungi that are commonly found in nature. These small microorganisms play a major role in the production of wine, since they are what allow the alcoholic fermentation of the must . In other words, they are responsible for transforming grape sugar into alcohol. Without them, no wine could see the light of day.
We speak more precisely of indigenous yeast when it comes from the natural environment surrounding the vine . It is found naturally on the skin of the grapes, but also in the environment of the vineyard, such as the air or the soil, the cellars or the framework. These indigenous yeasts then oppose exogenous yeasts, which the winemaker can select and add, and which do not come from the wine estate.
The spontaneous fermentation which is started under the action of native yeasts then makes it possible to obtain wines of great typicity , where the terroir is fully expressed.
The different types of native yeasts
The diversity of fermenting yeast strains is such that it is difficult to draw up an exhaustive list. However, fermenting must and grape berries often have the same yeast species from the natural environment. On the skin of grapes , the most common yeasts are:
- Brettanomyces;
- Aureobsidium pullulans;
- Candida famata.
We also sometimes find non-fermentative yeasts, such as Rhodotorula.
As for the fermentation must , the yeasts present are more from the Saccharomyces Cerevisiae and Saccharomyces Uvarum family.
To choose indigenous yeasts rather than exogenous yeasts?
The major advantage of indigenous yeast is that it is imbued with the typicality of the terroir . It then highlights the unique characteristics of the grape varieties, the soils, the climate and the know-how of the winemaker. This last point is important, because you should know that wines resulting from spontaneous fermentation with native yeasts require great attention. Indeed, it is always simpler to add industrial yeasts by carefully measuring the dosages, than to entrust this task to nature. We must then find the perfect balance in the vines and highlight biodiversity, so that native yeasts are sufficiently present to ensure good fermentation.
A wine vinified using indigenous yeasts then better reflects the work of the producer, who ensures constant vigilance and care for his vines.
This know-how and the typicality of the yeast are felt in the wine, because the selection of indigenous yeasts offers the wines complex and unique aromas . And since alcoholic fermentation is slower with this type of yeast, the wines are also sweeter.
Native yeasts for organic wines
The development of native yeasts requires some work and a lot of attention. We must then let nature express itself, and dare to trust it by intervening as little as possible. Logically, this approach fits perfectly into the production of organic wine . Whether with organic wine, biodynamic wine or natural wine, the producer who uses his own yeasts from his vineyard ensures a winemaking method that respects nature .
The use of indigenous yeasts to make wine is a daring bet, because this small microorganism is not so easy to control. But once the producer manages to tame these oenological yeasts, he can ensure that he produces a quality wine expressing the terroir with power and intensity.
