Autochthonous yeasts and Spontaneous Fermentation, what you need to know
If you are a wine enthusiast, you will certainly have heard of native yeasts and spontaneous fermentation. They pass it off as a fashion, because it is not a practice undertaken by the big producers, those who produce wine bottles as if they were industrial objects, but it is the secret to quality wine and therefore success.
Also the world's greatest wines are produced in this waybut it is convenient not to remember it.
Yeasts and Natural Wine
Yeasts are single-celled organisms belonging to the family of fungi, and when they are related to wine we always talk about the Saccharomyces cerevisiae which is produced by budding and is the most ethanol-resistant yeast. Normally, several yeast families are present in the early stages, but only they are not resistant to the impact of alcohol.
The yeast metabolism is very particular The yeast's metabolism is anaerobic when there is a high concentration of sugar, so that it follows the fermentation pathway rather than respiration, even in the presence of oxygen. Fermenting yeasts consume the sugars, producing alcohol and carbon dioxide.
It goes without saying that fermentation is a completely natural process, usually at spring temperatures, which does not require the use of laboratory-selected yeasts, yeasts which you can also buy on Amazon.
What are Autochthonous Yeasts?
I understand what you're trying to understand, where are these magical yeasts? There is nothing magical, it's nature!
In reality, a distinction must be made between two types of yeast that are genuine and good for spontaneous fermentation of wine:
– Grape cuticle yeastsnaturally present. If the grapes do not undergo any chemical treatment in the vineyard, these yeasts will be preserved until the moment of vinification and will be the winemaker's allies. It is clear that industrial producers first destroy the ecosystem in the vineyard, then they are forced to buy yeasts in the laboratory. A dog biting its own tail at the expense of those in whose glass their wine will end up.
– Autochthonous yeastsThe yeasts naturally present in the cellar, on the walls, in the tanks, in the pipes and even in the barrels. They are the magic!
These yeasts give the wine a flavour that typically reflects the grape variety whose must they will ferment, giving us a true, high quality product. Without shortcuts.
Spontaneous fermentation
No shortcuts really, apart from the option of using the Pie de Cuvea fermentation starter obtained from natural strains selected in-house.
As mentioned above, spontaneous fermentation usually takes place at temperatures ranging from 20 to 24 degrees, when the must is exposed to the air in the cellar in basins and is contaminated by yeasts, triggering spontaneous fermentation.
Although this is the noblest and highest quality way of producing wine, it exposes artisanal wineries to business risks, since fermentation may stop or not start at all. The winemaker needs to carry out a thorough study of the yeast strains present, and the good fortune of spring weather.
You know the artisan winemaker o natural is very complex and costly. Not using chemistry in the vineyard can expose them to risks of rot, fungus, which affect the quantity of grapes produced, which are selected manually by the winery. Not using stratagems in the winery either, as we have seen, exposes them to the risk of sub-optimal production due to the climatic and non-climatic variations mentioned above. Furthermore, apart from stringent requirements, they do not use added stabilisers, as sulphites, antioxidants, are also present in the cuticle of the grapes.
The result is a craft winemasterful and respectful of the production chain. And that it is fair to pay the right amount, which is not the embarrassing 6/7 euros of the industrial wines you find on the shelf in your favourite supermarkets.
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