Out Of Thin Air: A Quest for the Wild Yeast
For centuries the work of yeast was considered magical. We crushed grapes, let them sit for a few days, and surely, every time, the mix would produce wine. But no one really knew why. Bread and beer were similar. Those mixes “boiled” without heat, and their makers were viewed as priests as much as down-home cooks.
Things changed, of course. With a microscope we could see what had been invisible, and we took to acting like gods. Now we say a few things with pomp: Yeast is a one-celled organism from the kingdom fungi. It consumes sugars and expels waste as carbon dioxide and ethanol. Hence, the bubbles in beer and bread, and the alcohol in beer and wine. We now know yeast is high in vitamin B12. And protein. And folic acid. It is neither plant nor animal, but somewhere in between. We cultivate it. We harvest it. We use it and consume it and reap the benefits.
But there is a theory flitting around that yeast might have a lot to do with terroir, the “flavor of place,” the complexity of landscape. Terroir is a term often used when discussing wine, but in the last decade or so the concept has enamored a much wider scope of gastronomy. How do we taste place?
Might it be, say the wild yeast enthusiasts, that the flavor of place is as much about the small and the airborne as anything else?
But reality is this: Most vintners, brewmasters and bakers now use one strain or another of Saccharomyces cerevisiae, a yeast selected and bred for its specific qualities as opposed to where it might originate: flavor profile, aggressiveness, resilience to acidity or alcohol or both. It does rapidly in bread what would otherwise, in the case of a less vigorous starter, take “too long” to lift a loaf. And in wine and beer, this is the brewer’s yeast and “designer yeast” we mainstream consumers can thank for helping provide the same wine and beer consistently, time after time. They use this strain instead of allowing wild, spontaneous fermentations.
We want control, efficiency. And these are the central obstacles with wild yeast. There are enough variables involved in the production of beer, wine and bread even with cultivated yeast. And making them already takes enough valuable time. Let in the wild and things can get a little tense.
Robert Masullo of (the fabulous, incredible) Masullo’s Pizza in Sacramento uses a wild yeast starter as leavening for his pizza dough. He says there was a steep learning curve to working with it. It was wily. So although the pizza dough when they first opened was good, now it’s better.
Bookmark that idea: Time equals equilibrium.
For beer and wine, Brettanomyces, or “Brett” as it is coolly called, is the primary wild yeast in the industry. It is the culprit behind so many odd aromas not usually associated with pleasing the palate, aromas like “barnyard funk” and “antiseptic Band-Aid.” It can contaminate a batch of perfectly normal, inoculated lager, having taken the beer in a direction the brewmaster—and the consumer—neither planned for nor desired.
But it can also add intrigue. It can produce flavors like cloves and tropical fruit. And the other “bad” yeast essences can, in small quantity, act as more of a glimpse-in-the-mist rather than the unpleasant in-your-face action of a horse hoof.
In wine, Brett is practically anathema. Nearly everyone uses sulfur dioxide to kill any microorganisms like wild yeast, clinging to the grapes or hiding elsewhere in the must, whether potentially delightful or not. Talk about control.
On the bread side of things, Candida milleri and Saccharomyces exiguus are the prominent wild yeasts thriving in starters. They don’t lend such a swing of flavor possibilities, but there is no question that a bread made with a natural starter will taste different than one made with cultivated yeast.
Masullo’s pizza crust, again, is a good example. It is not at all sour, which could be a concern. Sourdough is nice but not all the time, and certainly not in pizza. His crust, instead, has a certain complexity of flavor. It does not taste vapid like a grocery store loaf of industrial bread. It tastes (and chews) like something elusive and precise and maybe even poetic—like sunshine on a field of wheat, the soul of the grain made manifest.
It tastes, in truth, like a good starter dough is supposed to taste: simple, with three or so ingredients, and yet, again, complex. Kind of like a successful wild beer or wine. Kind of like exactly what it is: a microscopic biodynamic farm, with layers of microorganisms, waste, nutrients and, thus, flavor. And, I might add, health. Natural starters take longer to work, and in the meantime the yeast breaks down more of the gluten in the dough. So natural starters make breads easier to digest for those of us with gluten intolerance. The biodynamic farm is in so many ways a healthier farm, making healthier food, with a myriad of yeast and bacteria working and eating and living into a crescendo of half-digested grain, in a good way.
But who has time for biodynamic farming? Who has the energy to forgo all our hard-earned technology and get quiet enough to listen to forces we’ve decided don’t exist or don’t matter? Who has the money to pay for it? Terroir is a nice idea—it sounds mystical enough—but daily practice? Leave that to the monks.
Admittedly, some people don’t even believe there is enough evidence that specific strains of yeast matter at all. Some people reject terroir altogether as an Old World, premodern superstition.
But for the sake of argument, let’s say terroir exists and yeast diversity matters. The good thing is that wild yeast really is everywhere. It floats in the air. It lands on lips, the hood of the car, the well-washed spatula. It is the white powder on the skin of the plum, the apple, the grape. Usable yeast is not just sold in little packages and pressed into cakes.
Unfortunately, there is quite a bit of the cultivated varieties of yeast floating around, too, and for our microclimate to stabilize after having been tampered with and tempted every which way, it’s going to need some time and space.
Sourdough starter keepers talk about “getting to know” your starter—discovering how best your starter thrives—how often it likes to eat, its favorite flour-to-water ratio, its ideal temperature.
This is what we have to do to find our terroir. We have to get to know our place. We have to get to know our yeast. The reason, I think, Brett has gotten such a bad reputation is that it sneaks in when the vintner or brewmaster isn’t looking and wreaks havoc. Many haven’t figured out how to make Brett play nice. Time equals equilibrium, remember?
In short, to discover the terroir of this place, we are going to have to wait. We are going to have to let mystery have her way again. There goes control. There goes efficiency, determination and drive. Things might get complex here. Things might go awry.
Maybe that isn’t such a bad thing.
Amanda Hawkins writes about food, place spirit and the connections between the three. She posts often on Enchanted Fig, a food site with stories and recipes that pendulum swing from highbrow cakes to humble feral offerings.