Wednesday, March 10, 2010

In Search of an Illahe Yeast.

To date, Illahe has done a handful of native fermentations but it hasn’t been a main part of the program. We’ve used a special yeast from Evesham Wood and we’ve used about 10 different commercial yeast. Most of the commercial yeast have given us wonderful results, so we have been happy. Yet from what Michael and I learned at the Oregon Wine Symposium, there may be a good reason to start looking at native ferments more closely.

Dr. Mat Goddard of Auckland University presented his research at the symposium that he had found yeast in fermentations that were genetic matches to yeast found in the vineyard. Not just yeast, but Saccharomyces—the wine yeast. This contradicts the research we learned in school. For example, Charles Edwards says in his book, Wine Microbiology on page 7, “Kloeckera…as well as others present in grape musts such as Candida [et al.] are also called ‘native,’ ‘natural,’ or ‘wild’ yeasts because they originate in the vineyard or the winery.” They are also called spoilage yeast, and they don’t include Saccharomyces. Moreover, in his section on native fermentations, he talks mostly about how spoilage yeasts affect wine.

Neither Dr. Goddard nor anyone else denies that these yeast do exist and do come from the vineyard. The important point is that Saccharomyces, if he is right, does come from the vineyard. But not only this, a vast array of different and interesting yeast with different genes come from the vineyard.

Isn’t this obvious? How was wine made historically if not from Saccharomyces? The explanations I had heard before were that yeast came from the winery walls and equipment and had floated there from oak trees, where they had been found before. Oddly, Dr. Goddard could not find Saccharomyces in the winery, though at some times of year it definitely exists and in great quantities.

The other fascinating thing about his discussion was that none of the yeasts he found were commercial strains, indicating that a wine can be made from its own terroir. Nonetheless, one of the components is bound to be the spoilage yeast of the terroir, so a native ferment will have to be managed closely.

In following Cristom and Eieio (whose excellent vin de terroir I had not too long ago) and many others, Illahe will begin a serious native yeast program this year. In the handful of native fermentations we’ve had, I had assumed they started from other innoculated fermentors. I still think it might have happened that way: a punchdown tool or even a hand moving from one fermentor to another to clean it could have innoculated the must. They were successful and acted like innoculated fermentors, but this research suggests that these wines may have been native Illahe yeasts. Finding a local, strong fermenting yeast would be something that we would love for complexity and uniqueness.

Brad Ford

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