In case you have been living under a rock or preserving your remaining shreds of mental health by avoiding all forms of social media—in which case, good for you—everyone is baking sourdough. Crusty, artfully scored loaves have gone from the domain of professional bakers to a tech bro flex to the literal daily bread sustaining people of all stripes through a crisis. In San Francisco, tins of starter have even begun popping up on trees. All over the country, people are ditching their keto diets in favor of loaves with brag-worthy crumb structures.
Sourdough was feeding civilizations long before it became a trendy emotional coping mechanism. Archeologists have uncovered evidence of bread-baking dating back 14,000 years, long before Louis Pasteur cracked the code to isolating and developing commercial yeast in 1859. There’s compelling evidence that the ancient Egyptians baked with sourdough starters, most likely after a baker accidentally left a flatbread dough out long enough that local microflora began to ferment it. Many starters have been passed down for generations—some archived in the Puratos Sourdough Library in Belgium are reputed to be centuries old.
“Essentially, a sourdough starter is a living culture of yeast and bacteria. From that, you can make loaves for the next 500 generations of humans,” says Zachary Golper, the James Beard finalist behind Brooklyn’s Bien Cuit bakery and the author of Bien Cuit: The Art of Bread. “You can change locations, which will change its flavor, but as long as you maintain it, your great-great-grandchildren can use it. This is a culture that you’re keeping alive. It’s your mother.”
Wild fermentation has always been a part of the human diet until very recently. We’ve limited ourselves by drinking beverages that are coming from single strains of yeast.”
In many ways, sourdough’s rise, fall, and rise mirrors that of the spontaneously fermented wild ales. Both ancient methods were more or less de facto prior to industrialization. In the United States, it wasn’t until the 20th century that commercial yeast production boomed and wild-fermented breads and beers were relegated to relative obscurity.
“Wild fermentation has always been a part of the human diet until very recently. We’ve limited ourselves by drinking beverages that are coming from single strains of yeast,” Golper says. “For hundreds of years, all this was done through wild fermentation and then almost overnight, everything changed. Sourdough bread is the best bread, so why wouldn’t we want to have wild-fermented beers?”
The truth is that the two crafts aren’t so different from one another. Lactobacillus, the helpful bacteria that gives sour ales their distinctive funk, is also part of the microbial makeup of a sourdough starter. Historically, the arts of baking and brewing evolved in tandem, often in the same facilities, which allowed for microbial cross-pollination.
“Oftentimes, the bakery and the brewery existed in the same location originally because if you’re making bread, it’s very easy to simply shift the hydration a little bit and all of a sudden you have beer,” says Lauren Grimm, who co-founded Grimm Artisanal Ales with her husband Joe. “Sourdough bread is incredibly close to beer because it has almost the same ingredients. When it comes to sourdough, you’re not only using Lactobacillus, but there’s also a combination of yeast that are actively fermenting the grain.”
With their Brooklyn temporarily taproom closed for in-house, Lauren and Joe have been ramping up their own home fermentation efforts. Though they haven’t quite gotten into kombucha yet, their kitchen is crammed with all manner of pickles, kimchi, and sourdough starter.
“It’s kind of become an obsession. Every day that I have off of work, I’m at home baking too many loaves of bread,” Lauren says. “Once you understand the nature of fermentation and souring, you realize that all of these foods that we love are based around the same ecology of microbes. All of them could use almost the same microorganisms to create those acids and really delicious flavors through fermentation and time.”
Lauren and Joe have spent years nurturing and tweaking their brewery’s own distinctive mixed culture, the blend of wild yeast and bacteria that gives their sour ales their unique character. Since bread and beer go together so perfectly, they decided to give their culture a new home in the form of a starter.
Once you understand the nature of fermentation and souring, you realize that all of these foods that we love are based around the same ecology of microbes.”
“We thought it’d be fun to take some of our mixed culture from our brewery and start a sourdough culture based on our brewery’s own ecosystem of Lactobacillus and yeast,” Lauren says.
Adding sour beer to the equation has the added benefit of dropping the pH of the mixture. Essentially, the extra acid creates a hostile environment for some of the unwanted bacteria, allowing the desirable microflora to flourish. It’s a process that would naturally occur on its own after a few weeks of consistent feedings, but the addition of fresh pineapple juice or a sour beer can jumpstart it.
“You’re putting in beer that already has beneficial bacteria and yeast and then they can have a good environment to take off and colonize your starter,” Lauren says. “When the pH drops, it becomes more acidic and the gross bacteria can’t survive. Then you all of a sudden have this really wonderful concentration of Lactobacillus and yeast that start to colonize your starter.”
Like others baking and homebrewing right now, the Grimms have been finding a sense of community through the process. By now, just about everyone working in the brewery has their own sourdough loaves going. Since small bags of flour are still scarce in some areas, the staff have started going in on 50-pound sacks from wholesale suppliers. As someone who now has other expert brewers to oversee the nitty-gritty details of beer production, Lauren appreciates being fully engaged again in the process.
“I’m like, ‘I have my hands in the dough! I’m really on top of all the aspects of fermentation!’” Lauren says. “It’s amazing how obsessive everyone at the brewery is about making sourdough at home. A few people asked us to bring in our sourdough culture for them and everyone’s sharing pictures of their open crumb.”
Until recently, life looked dramatically different for all of the staff. Lauren acknowledges that before the lockdown, she was more likely to buy bread than make it. Yet while she certainly never wished for the current situation, the act of baking dense loaves of rugbrød, a dense Danish rye sourdough, and sharing tips with her colleagues helps give a rhythm and structure to the days.
“When I walk around Gowanus, I see my neighbors cooking, gardening, watering their indoor plants, and spending time with their families. It feels like life from another time,” Lauren says. “At this moment, we’ve been enjoying getting back to our roots and baking bread. More and more we have conversations about what it was like starting our business, about homebrewing and fermenting 15 years ago when we first met. Sharing meals with our bread has become this kind of wonderful moment of gathering within our small family unit.”
Not far away in Brooklyn, Golper is also watching his levain turn into loaves that continue to feed the city of New York. Since the pandemic began, he says he has been flooded with email questions about the best ways to bring a starter to life. Although he’s had success with the beer method, he says he personally prefers his wild-fermented ales on the side.
“To me, sour beers taste perfect and they just feel good inside,” Golper says. “You could use a lambic with your starter—I’ve done it—but for a guy like me who's trying to avoid too many trips to the store right now, I’d rather just drink the beer.”