Natural Yeasts and Terroir

Here is a quote from Philippe Pacalet, wine maker in Burgundy. Pacalet wrote an introduction to Jules Chauvet's "Etudes Scientifiques." Chauvet is thought of as the father of natural wine making in France, and Etudes Scientifiques is a collection of his studies and writings. This quote is lifted from an article on the Chambers Street Wines website. The whole essay is worth reading, but this quote particularly caught my attention:

The entire theme dedicated to indigenous yeasts is eloquent on this subject: to make a wine of terroir, one must utilize the biomass (yeasts, bacterias, funghi, microbial life) existing in this terroir. The quality of these native yeasts, that is to say their biodiversity, is essentially tied to this notion of terroir. The different types of yeasts which succeed each other in the course of the alcoholic fermentation are thus a “key” which reveals to us the vineyard’s unique characteristics and typicity.

Makes sense, right?

Mark Vlossak makes wine at St Innocent, one of my favorite Oregon producers. Three out of every four years, as conditions allow, Mark uses no sulfur dioxide during fermentation. Sulfur dioxide suppresses the natural yeast strains, and he doesn't want to do that. He likes "the things that grow" without sulfur dioxide during fermentation, what they add to aroma and flavor. But Mark says that the natural yeasts at his disposal cannot ferment past 5 or 6% alcohol and often produce "stinky" by-products. Here is what he said when I asked him whether or not using natural yeasts is important to him:

There are no unnatural yeasts. All yeasts used to make wine are derived from indigenous cells. Just like vines are propagated from cuttings, sometimes from other places, yeasts are derived from cells. The real question is, are the yeasts a good match for the terroir and the wine you are trying to make.

This also makes sense, right? If the natural yeasts cannot turn juice into wine, or do so but also contribute nasty aromas, then you have to supplement with other yeasts. The question is not whether or not the wines taste good, but do they express the terroir in the Dundee Hills or in whichever of St Innocent's plots we are talking about?

Greg Sandor of Bridge Urban Winery talks about how exciting it was for him to participate in an experiment at Cornell University in which 40 different yeasts were used to ferment the same grape juice, about tasting the results and determining which strain makes the best wine. I don't know if he brings that approach to making wines at Bridge, but if he did, would that render his North Fork of Long Island wines terroir-less?

Can wine express terroir without naturally occurring yeasts? Must you use only the naturally occurring yeasts, or can they be supplemented with industrial yeasts? There are people with very strong opinions on this issue. I am not one of them, as I just don't know enough about it.

But I will say this - insisting that nothing "unnatural" be added to wine might rule out a lot of wines in the terroir department, most Champagnes and many Burgundies, for example. Sugar, a human-made chemical no more or less natural than sulfur dioxide is added to Champagne in the dosage, and to some Burgundy wines if they are chaptalized. So do only non-dosage Champagnes and un-chaptalized Burgundies express terroir? I think you can shoot yourself in the foot trying to make hard and fast rules.

I gravitate towards the Pacalet way of thinking, which I see as akin to the Alice Waters way of cooking and eating. But I don't think of it as "correct" in a universal sense, something that everyone should do, like thou shalt not use unnatural yeasts or something.

For me wine is food, and I like to learn about the ingredients before buying it. Loading this information on a wine label is impractical, expensive, and unromantic. It would be great if there were some cost-effective way to gather and display this information so that interested consumers can go to one source before making purchases.