Indigeneous Yeasts - Myth or Reality
The ISV (Institute of Vine and Wine Sciences) just published the results of a study regarding over 200 wines vinified in 2012 and whose objective was to measure the genetic variety of yeasts used.
As a reminder, yeasts are the micro-organisms in charge of alcoholic fermentation of wine by transforming the sugar into alcohol.
The results are interesting and seem to indicate that yeasts are not specific to a given area:
- Yeasts present in a given area have no genetic specificity: the various strains analyzed in a given area are not members of a same genetic family which would be suited for this area, most of them are found in several different areas or even regions,
- The nature of yeasts present in a given area evolves from one year to the next : some strains last, some appear whereas some just disappear. Strains would therefore only be “in transit” in a region/farm and not “settled”,
- Finally, no strain (regardless whether it’s commercial or not) has supplanted other strains present in a given place.
The only exceptions which confirm the rule are the Bourgogne and the Champagne where all the strains come from a same family and they appear to be more resistant to acid vinification conditions of these wines.
So if this study shows that there is no specific yeast for a certain region or farming area, it does show that this specificity indeed exists, but for the type of wine, so the wine variety/climate pair.
For more news on Rhône wines: www.vins-rhone.com
Source: “Réussir Vigne” – No. 208 – The specificity of the indigenous yeast is a myth