Food for Thought
The art and science of fermentation
At a Korean superstore in Las Vegas, I watched an employee whose sole job, it seemed, was organizing a vast array of kimchee. Her domain consisted of thousands of plastic tubs of fermented fish and vegetables in various combinations, usually spicy. She darted about the immense display cases and scrutinized the tubs' arrangement, rearranging their contents like beads on a giant abacus.
My feeling observing her that day roughly sums up how I feel about the process of fermentation generally: a mixture of awe and fear. The process is like some potent voodoo that could give you special powers or torture you to death.
Letting food sit at room temperature and become colonized by airborne microorganisms runs counter to everything we're taught about food safety. But without this guided decomposition that we call fermentation there would be no bread, cheese, tequila or kimchee.
The Art of Fermentation, by Sandor Katz (Chelsea Green), is therapy for my split impulses regarding fermentation. It's a hefty book (with extensive citations) that exhaustively explores the world's fermentation traditions for vegetables, fruit, meat, dairy and other foodstuffs. It recounts much of the history of this ancient art, right up to contemporary times, and it's rich in practical knowledge that you can start applying immediately.
The book has given me the confidence to play with the process—and the understanding to ferment fruits and vegetables from my garden. I hope to become proficient enough to put away significant quantities of the summer's harvest via fermentation. In other words, I'm into it—the process and the book. And I'm not the only one. At last check, The Art of Fermentation sat at No. 14 on The New York Times best-seller list.
In the forward, Michael Pollan writes that "Katz's book is the main reason that my kitchen counters and basement floor have lately sprouted an assortment of mason jars, ceramic crocks, jelly jars, bottles and carboys, the clear ones glowing with unearthly colors." Anyone who reads this book might just find their own house similarly cluttered.
My own fermentation-ware collection is rudimentary compared to Pollan's, but I've already caught myself looking at a beer growler in a new light, and I doubt it will be long till I spot a crock at a yard sale. In my three-week fermentation career I've already learned some important things, like how much more peaceful fermentation is than canning, and how easy it is to make booze that doesn't taste terrible. Too easy, really.
When Louis Pasteur demonstrated that many diseases are caused by living germs, the "war on bacteria," as Katz calls it, was officially on. Many lives were saved by the bacteria-killing process that became known as pasteurization and its spawn—the countless methods that use heat, pressure, acid and other means of preserving food by killing all the microorganisms in and around it. In short order, these methods widely replaced fermentation as the preservation method of choice.
While modern canning techniques work by killing, fermentation takes an opposite approach: promoting life. Specifically, the growth of bacteria and yeast that gradually create an alcoholic or acidic environment in which only certain microorganisms can live. "In this environment, Salmonella, E. coli, Listeria, Clostridium and other food-borne pathogens cannot survive," Katz writes. The playing field is tilted to favor either lactic acid bacteria like Lactobacillus, or certain yeasts like Saccharomyces, to which we owe bread and booze. Katz quotes USDA vegetable fermentation specialist Fred Breidt as saying there's never been a documented case of food poisoning from fermented food. "Risky is not a word I would use to describe vegetable fermentation," he continues. "It is one of the oldest and safest technologies we have." Bacterial contamination on raw vegetables, by contrast, Katz points out, sickens people on a near daily basis.
In the tropics, long-term storage of fermented products is difficult because of the incessantly hot weather. Luckily, food grows year-round in that climate, so storage isn't necessary. Conversely, the places with the shortest growing seasons have the widest window of cool weather during which fermented products can be stored. Katz regularly stores fermented food all the way to spring, when food starts growing again in the hills of Tennessee, where he lives.
Katz refrains as much as possible from giving exact recipes. He instructs with broad strokes rather than micromanagement, teaching the principles behind each step in the process. That said, the book will give you a firm start on any fermentation path you could possibly wish to follow. In many cases it's the only source you'll need, from making miso to fermenting mashed potatoes.
Embracing fermentation involves a truce in the war on bacteria. Such a peace means accepting that the microbes are basically in charge. In fact, "we" are mostly "them." Of the 3 million genes identifiable in our bodies, only 30,000 are human genes. The rest are bacterial, representing thousands of species.
Making peace with microbes means understanding where and how and when they can hurt you. The first and foremost rule for novices: Avoid fermenting animal products until you know what you're doing. And while this will come as a blow to some, dark leafy greens such as kale can be traumatizingly foul-tasting, if technically nonpoisonous, when fermented.
I've always been an old-school pickle-maker of the water-bathing, vinegar-brining, pressure-canning, kill-em-all school of food preservation. As I explore fermentation, it's a relief to leave behind the heavy artillery that canning involves, not to mention the heat of the kitchen. So far I've made some hooch from sun-dried apricots, a batch of barely fermented sun-dried apricot jam that's got a telltale tang to it and a pint jar of mixed garden veggies: snow peas, baby carrots, garlic flowers and squash blossom buds. After three days my veggies started to turn acidic. You can open a fermenting jar of pickles, unlike vinegar pickles, whenever you want for a snack. The flavors are strong, new and often weird. But when done right, like at the Korean superstore, fermentation offers a nearly endless myriad of delicacies that I'm looking forward to exploring.
by Sandor Katz
Chelsea Green, hardcover, $39.95