There is a moment in the life of fruits and vegetables that has always puzzled and fascinated me. Put out a dish of strawberries, and in days some darker spots will appear. Maybe a thin tendril of mold sprouts out from the strawberry’s body. At this point, you can still eat it, simply by cutting off the moldy bit. But all of a sudden, the strawberry has clearly died. It’s inedible, sour. It has passed over in to the world of bacteria, mold, and minerals-it is no longer a self-regulating organism. It has stopped being an individual, but has become multitudes.
How does this happen? When is an organism living, and when is it dead? When is an organism living, and when is it dead? Where does death come from, and why does this change of state happen so quickly? Amazingly, we’ve developed some techniques to play with this boundary between life and death, stretch it, and blur it.
Vietnam’s Low-tech Food System Takes Advantage of Decay – ” Fermentation is both low-tech and democratic. It can be a fundamental component of a sustainable food system”
At the entrance of a market in Hanoi, a woman with a dưa chua stand tells us that making ‘sour vegetables’ is easy: you just add salt to some cabbage and let it sit for a couple of days. As we talk, several customers come by, eager to scoop some brine and cabbage into a plastic bag. Worried that we’re discouraging her customers, she shoos us away. She isn’t lacking business.
Is fermentation really so effortless? The short answer is yes. Many recipes will call for two things: water and salt. At just a 1:50 ratio (2%) of salt to food, you can create an environment undesireable for all the bad bacteria and encourage all the good ones. Sauerkraut, kimchi, fish sauce, sriracha, and kosher dill pickles-are all made according to this principle.
Yet other types of fermentation are a bit more complicated. They call for sugar (e.g. wild fermented alcohol like ethiopian honey wine), yeast starters (rượu nếp, most wines and beers), special fungi (tempeh, miso), or some kind of combination of fungi, bacteria, salt, or sugar (kombucha). Yet others are simpler: to make cooking vinegar, just let that bottle of bad wine sit for a couple of days, and to make sourdough, just mix water and flour and leave it on your counter.
All in all, fermentation is just controlled decay: your most important ingredient is time. This can sound like a bit too much, too fast. Take the woman I met at the entrance of the market. Her dưa chua, while in great demand, looks like wilted cabbage, soppy, floating in murky brine. Some bubbles are forming on the edges of the plastic container-for the trained eye a sign of an active fermentation process, but for the uninitiated, an alarm bell.
There’s no use beating about the bush. That dưa chua is in fact rotting in a very similar way that a peat swamp is constantly rotting, belching large doses of methane into the world. What’s happening is an anaerobic fermentation-that is, without significant amounts of oxygen. This absence of oxygen and the high levels of salt creates an environment supportive to several bacteria that also find their home in our own digestive systems.
When I was a kid, every pickle my father ate was a bit of a disappointment. Dad, who grew up in the 1930s and ’40s in the Bronx, New York, remembered plucking kosher sours out of barrels filled with cloudy brine-“Now those were pickles!” he’d tell us. I only knew Claussen and other vinegar-cured pickles, the kind you buy in jars off the supermarket shelf, and I liked them just fine. But when I finally tasted a real pickle-the kind made the old-fashioned way, fermented with nothing more than salt, water, and time-I realized what I had been missing. A vinegary pickle plows through your palate with its tartness (often in a most pleasing way), but a live-cultured, salt-cured, fermented one tells a more multifaceted story. It is sour, to be sure, but it tastes of something more, something elusive: It’s the flavor of Middle Europe captured in one bite.