If you use wild yeasts to vinify your wines, why do you do it, and what advantages does this approach offer? And if you strictly use commercial yeasts, why do you prefer this approach?
Jason Haas, Tablas Creek Vineyard (Paso Robles, California). We believe in wild yeasts for a few reasons. We think that the collection of yeasts in our little corner of the world is unique, and that its reflection in the wine is an essential piece of our terroir. We also like the fact that it gives us a natural cold soak at the beginning of most fermentations, as it takes a little while for the indigenous yeasts to build up a sufficient population to really get fermentation going. And we think that the many different strains of yeast that are active must be contributing different flavors that in the end will add to the complexity of the wines that they help make.
But mostly, we like it because it works, and has worked for us with every lot, every year since we began fermenting grapes in 1994. And I think it’s important, if you’re going to use wild yeasts, to be consistent about it. Producers who do a “wild” yeast fermentation next to their cultured yeast fermentation are, to a certain extent, deluding themselves. The yeasts that you release in one tank don’t stay put; they travel, and they embed themselves in the infrastructure of the cellar. Neil, our winemaker, calls these “feral yeast fermentations,” which sounds about right to me.
At Tablas Creek, we have been careful to never use cultured yeast in our history. So we believe that we do have a unique population of yeasts here at the winery. Are some of them refugees from other wineries nearby? Quite possibly. But when we started, we were the only ones in our immediate vicinity, and I think we have as good a chance as anyone to actually have true natives. And they’ve worked for us every year, which, in the end, is what matters.
Alberto Antonini, Wine Consultant (Italy and Argentina). I’ve been using wild yeasts for the making of premium wines for 12 years and I’m the happiest person as I’ve gotten great results. What’s the point of killing all the natural yeasts that are on the berry skins and responsible for complexity and sense of place and replacing them with a strong yeast strain that can be used by any wine producer in the world? What’s the point of using a yeast strain that often comes from vineyards thousands of miles away? Why there should be only one yeast strain fermenting—as opposed to the hundreds or thousands of yeast strains that are on the berry skins, which, like an orchestra of many instruments,create a lot of complexity in the wine?
What should we be afraid of when we grow premium grapes and all the yeasts on the berry skins are responsible for the fermentation? The use of commercial yeast makes sense just for commercial wines and not for premium wines, as these yeasts work faster and guarantee boring standard flavors.
Bernard Hervet, Domaine Faiveley (Burgundy, France). Regarding your very interesting question about the use of natural or selected yeasts, we make up our mind according to the vintage year. For red wines, we mainly use selected yeasts to get more precise, pure wines. During the winemaking process, when the harvest is perfect, we use natural yeasts. We have noted no significant difference for the pinot noir.
For white wines, we use more and more natural yeasts so as to improve the complexity and the length of alcoholic fermentation. Natural yeasts are more slow-moving and extending the fermentation enables us to increase the complexity of the wine. We obviously act this way when the sanitary state of the vineyard is good.
Laurence Féraud, Domaine du Pegau (southern Rhone, France). I only use wild yeast. In the hot 2003 vintage the overripe grapes had high sugar content and it was difficult to finish the process. It was the only vintage when I used commercial yeasts to help to go to the end of the fermentation process.
On the second day following the picking the process starts. That’s why I don’t use any commercial yeast on the red wine. Temperatures are not controlled. The yeast’s activity and multiplication depend on an open air or closed pump-over. It is true that various yeast type are more or less ?? and give various aromas in the wine. But that result becomes a part of the vintage style.
Yeasts are also the result of a vineyard’s culture. When there isn’t any chemical treatment in the vineyards, yeasts are efficient.
Philippe Guigal, E. Guigal (northern Rhône, France). If you use wild yeasts to vinify your wines, why do you do it, and what advantages does this approach offer? What are the risks involved in using wild yeasts? Can you make a true vin de terroir if you utilize commercial yeasts? If you make some of your wines using indigenous yeasts and others using selected strains, are these various wines aimed at different segments of the wine-buying population? Etc.
We do not use selected yeasts and are very happy to use our natural yeasts. Through our experiments we have found that our natural yeasts easily express attractive, pure aromas, good color and nice tannins and give a real integrity to the wines. These yeasts are naturally strong on the reds. A vintage like 2003 had extremely high potential alcohol, low nitrogen, and so on, but we did not have a single accident. Therefore, we believe that these yeasts or combination of natural yeasts are flexible and well adapting.
We also know that with the low temperatures used for the white wines, the natural yeasts are a little bit weak, but we use their bad tolerance to cold temperatures to get longer alcoholic fermentations with the Condrieu, for example. Long fermentation = more fatness and richness in the final wines.
Before moving to other places when I was an enology student, I could not understand why all winemakers were not using natural yeasts but I have seen places where the natural yeasts were really bad: producing high levels of volatile acidity, stopping their work quickly, even at a low alcoholic degree, producing brett, etc. Now I use to say that if you have the chance to get good natural yeasts, it is better to keep them but I respect people using selected yeasts because of my experiences as a stagiaire.
I believe that natural yeasts can be a strong factor in the purest expression of the terroir. There are many very good wines made with selected yeasts but the terroir is sourced by many factors and I would say that natural yeasts is one of them.
Pietro Ratti, Renato Ratti (Piedmont, Italy). If grapes are in good and healthy condition (like now, in this good 2012 vintage), I normally use wild yeasts. I like to let the fermentation start and run naturally, and I also don’t want to waste money if it’s not necessary!
Of course, if there is a difficult harvest (like too wet or too dry grapes), I’m not against adding commercial yeasts. Because to make a good wine it’s extremely important to have a complete and smooth fermentation.