"All fermentation is a form of pickling, but not all pickling is fermentation," says Austin Durant as he takes me on a tour of his various projects. By "tour," I mean he sets down several jars of fermented goodies and I happily sample them all. From a smooth Finnish yogurt called viili to a complex, delicious kimchi lacking the monotonous sourness of its store-bought counterpart, I become more and more taken by the power of yeast and bacteria.
Yeast is indispensable if you love beer or bread. I love both. Yet, I don't think of yeast when it comes to vegetables. Many of Durant's projects use yeast and bacteria from our environment, a process also known as wild fermentation. It's simple: Mix the ingredients, place in an open container and allow the process to unfold. The idea is to provide a medium for growth while adding the necessary flavors to finish the dish. Yogurt requires an active culture, like Durant's Bulgarian yogurt, which came from a friend's starter.
Fermentation occurs when organisms consume glucose (sugar) and metabolize it to ethanol (alcohol), which is what we see in drinking-alcohol production. Remove oxygen, however, and the organisms convert glucose into lactic acid. Acid breaks down the vegetables and gives them the tang associated with sauerkraut and kimchi. Often, storebought brands cheat and use acetic acid (vinegar). That's pickling, but it's often sour and not much else. Fermenting is more time-consuming and results in a greater depth of flavor. There are bacteria that convert ethanol into acetic acid, so acetic acid can be a component in food fermentation, but it isn't the only ingredient.
Durant has a ceramic jug with a spout in the bottom. The top is covered with cheesecloth and inside is a white, gelatinous bloom that looks like a jellyfish roosting in a pot of iced tea. From the spout comes kombucha, a drink that's become popular in the U.S. The jellyfish-like substance is layered with each new generation, like tree rings. If Durant wanted a new batch, all he'd have to do is peel off one of the layers. Placed in an appropriate container and with brewed black tea added, there'd be a new batch of kombucha when the critters finished fermenting. While the yeast converts glucose to ethanol, the bacteria convert ethanol to acetic acid. That's where kombucha gets its puckering tang.
Fermented foods have a rich heritage in many cultures and known health benefits, not to mention being just plain tasty. They're rich in nutrients and add to our symbiotic gut flora. Requiring little energy to produce, fermentation is an economical way to create complex flavors in food. Durant's kitchen is a clean space with shelves of jars and ongoing projects in a small alcove. The kombucha vat sits on the counter. Everything is neatly labeled with names and dates, a must in fermentation, where timing is important.
So, where's the line between fermenting and rotting food? Durant notes that the acidic environment produced in fermenting naturally inhibits growth of bad bacteria. Even the yeast and bacteria involved in fermentation are controlled by their own acid tolerances, so overgrowth is generally not a problem. When fermenting, it's important to use your senses. If your senses tell you something went wrong, then something did.
Durant walked me through his journey with food and fermentation, beginning with an exploration of his relationship to food and leading to the Fermenters Club (tips and recipes on the website), an organization he started with friends in 2011. They'd meet to trade tips and the fruits of their latest projects. Durant's inspiration and education came from many sources, but he cited Sandor Katz's Wild Fermentation as a great place to start. He's also teaching classes in San Diego, with some offerings at City Farmers Nursery (4832 Home Ave.).
If you're interested in fermenting, it's lowcost and requires minimal materials to start: a large jar, ingredients and a cloth. Empty wine bottles make excellent weights to keep vegetables submerged and the cloth wraps neatly around it as a "lid." You need the contents open to the atmosphere, but you don't want dust or debris falling in. Once everything's set up, the organisms are given time to ferment.
Since food swapping is a part of the Fermenters Club, Durant asked if we could trade my homemade granola for his kimchi. At this rate, I might trade my firstborn. Durant's enthusiasm, and his delicious kimchi, had me out shopping for glass gallon-sized jars immediately. If my results are anything like his, it'll be well worth the wait.
Write to email@example.com and firstname.lastname@example.org. Marie blogs at meanderingeats.com and you can follow her on Twitter at @MeanderingEats.