More Evidence Linking Fermentation and Complexity: Wild-Fermented Wine

I came to believe that we need to eat fermented foods to be healthy partly because this idea solved an evolutionary question: why do we like food that is sour, umami-flavored, and complex? I realized that all three preferences could be explained the same way: All three push us to eat more fermented food. For example, fermented milk (yogurt) is sourer than fresh milk.

Fermentation also increases complexity. An example is miso. I noticed that miso by itself was sufficient flavoring for soup. I had to add quite a few spices to produce the same amount of complexity that miso alone produced — miso was a super-spice.

Wine is a fermented food, of course, but long ago all fermentation was “wild” — it proceeded from whatever fermenting agents were in the air, on people’s hands, and so on. Fermentation increased complexity not just because the microbes metabolized the food but because there were many kinds of microbes. Australian winemakers were recently given a lesson in the connection between wild fermentation and complexity:

We were tasting two glasses of pinot noir, blind, and the questions were: is there any difference between them? If so, how are they different?

Glass One was full purple-red in colour and smelled fresh and fruity, delightfully primary, with a bright raspberry aroma that was almost like bubble gum. It was pristinely clean, delicate, light on the palate and charming, but ultimately rather simple.

Glass Two had a darker colour and blacker fruit aromas, more complex and mysterious. Similarly, in the mouth it was fuller-bodied, richer and deeper, with greater textural interest, fleshier and denser, with more tannin. A beautiful wine, too, but much more profound and captivating than Glass One.

Winemaker David Bicknell then announced to the gathering [of winemakers] that the only difference between the wines was that Glass One had been fermented with a pure yeast strain and Glass Two had undergone a wild ferment. That means no yeast had been added: the juice had been fermented by whatever yeast strains happened to be in the air at the time.

“Both wines were picked from the same Upper Yarra Valley vineyard on the same day, and everything in the winemaking was the same except the yeast,” announced Bicknell, who is the winemaker at Oakridge. The class was asked to try to pick the wild ferment and say which wine they preferred. The great majority nominated the correct glass, and liked it more. There was nothing wrong with Glass One: it was simply that Glass Two was better – every way you looked at it.

The “class” was a wild-yeast workshop at the recent Australian Wine Industry Technical Conference in Sydney. The “students” consisted mainly of experienced winemakers. . . . The environment, especially the air, contains hundreds of thousands of strains of yeast, most of which occur naturally. The species present depend on what flowers, fruits, trees and grasses are in that locality. Recent New Zealand research has shown that yeasts are territorial, and the species present vary according to the place. . . .

Pairs of Hardys’ Eileen Hardy chardonnay and Mount Pleasant Hunter chardonnay, all 2013 vintage, one of each “wild” and the other seeded with cultured yeast, showed more permutations of character. With Mount Pleasant, the wild wine was cloudy in appearance, and quite stinky, but also showed density of flavour and richness, while the regular wine was good but not as interesting. The winemakers seemed to think the stinky one would clean up after a period of lees-stirring.

Of the Hardys wines, the regular ferment looked bright and clear in the glass, and was pristinely clean, intense and lively, with a spring water-like lightness of texture. The wild ferment was cloudy, smelled of cashews, bread, smoky oak, sulfides and spices, but the real difference was in the mouth. Its texture was far more rich and dense, fleshy and rounded, smooth and harmonious.

Eileen Hardy winemaker Tom Newton said he believed the sulfides were related to the wine’s greater textural density. Indeed, all winemakers I’ve quizzed who practise wild fermentation believe it gives their wines greater length of palate and improved texture as well as extra flavour complexity.

Even riesling responds to this ”rougher than usual handling”. Kerri Thompson’s wild-ferment Clare Valley riesling was a graphic illustration. Served beside a conventional Clare riesling, which was a perfectly good wine in its way, her KT Pazza Riesling 2013 was turbid (not clear) and smelled of apple, pear, yeast and a hint of nuttiness from time spent in old barrels. It was a more expressive, more textural and more layered wine than the conventional one. It’s on sale soon at $29.

And perhaps the most beautiful, exotic, fascinating wine of the day was Cullen’s Kevin John Chardonnay 2011. . . . Biodynamically grown and wild fermented, it’s a pioneer and benchmark of the genre. It’s so complex it’s difficult to describe, although honey and oak and what I call “balsamic” (like the smell of balsamic vinegar, without the vinegar or sweetness) aromas are all involved, welded to a razor-sharp, crisply tart, long and linear palate structure.

Will Australia become the new California? Decades ago, California winemakers figured out how to make wines that were the equal of French wines. No doubt French winemaking had stagnated. Australian winemakers have just been taught how to make much better wines for the same price. As far as I know, Californian and French winemakers have yet to learn this lesson.

Wine is a very old food. One remarkable thing about this demonstration is how long it took — how long it took to learn this lesson. Sure, we like hand-made this and artisanal that, but in so many ways we prize uniformity, no more so than in our educational system, to which we entrust the most precious thing we have: our children. Who are treated by that system in a factory-like way, in the sense that all children in a class get the same teaching materials and are given the same tests. I have yet to hear an education theorist say that the best education produces diversity not uniformity. When I let my students’ underlying diversity be expressed (for example, in what they chose to learn), teaching became much easier. Win-win. Essentially what the winemakers are figuring out: When you let the natural variation of yeasts be expressed, making great wine becomes much easier.

5 Replies to “More Evidence Linking Fermentation and Complexity: Wild-Fermented Wine”

  1. Allow me to recommend a birthday present wine I got from my daughter: Assyrtiko 2012 Wild Ferment from the Gaia estate, Santorini. Yum, yum.

  2. I bake bread, mostly sourdough. I use a long fermentation time – usually 12 – 16 hours. It’s well known in the baking business that longer fermentation times lead to more flavor. Some of that is just time hydrated (wet) aside from any fermentation, but fermentation also plays a big role.

    I did an experiment in which I used a pinch of conventional yeast to make one batch of dough, and my regular sourdough culture for another. The recipes were adjusted to have the same overall amounts of flour and water, and the pinch of yeast was selected to give about the same fermentation time as the sourdough batch would take.

    The result was that both batches fermented, handled, and baked essentially the same as each other. The sourdough bread clearly had better and more complex flavor.

    I’d done the same kind of thing before, with similar results, but this time I made sure that the recipes and fermentation times were the same so as to get a more controlled comparison.

    In developing a sourdough culture, it’s often said that you get wild yeast from the air. That may be so on occasion, but I have reasons (I won’t go into here) for thinking that most of the yeast arrives with the flour you use to create the sourdough culture. Eventually the culture stabilizes with a mixture of yeast and lactic and acetic acid bacteria. It’s the mix of all three that gives the fine sourdough quality – the complexity that Seth talks about.

  3. Seth, apparently there isn’t really any such thing as a true “wild yeast” fermentation. Rather, when they’ve actually looked into it, regardless of what yeast starts off, they’re all out-competed in fairly short order by dominant commercial wine-specific yeast strains.

    Seth: The article fails to explain why the supposedly wild fermentation wines tasted much better in the Australian taste test.

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