When Aniko Zala first nibbled on kimchi, the spicy Korean cabbage mixture bit her back.
“I always loved sour flavors,” she said. “I couldn’t handle the funk at first.”
The dish eventually grew on Zala, though, and kimchi is now one of many fermented foods that she makes and stocks at her Blendon Township home.
Although the pungent aromas and occasional scum of fermentation can be overwhelming to novices, the method of preserving vegetables, grains and dairy need not be.
“People think it’s a lot harder than it is, and that you have to be more precise than you need to be,” said Zala, who runs Wild Origins, a local herbalist business. “You only need a jar, some vegetables, some salt and some water.”
Fermentation's surge in popularity is actually a resurgence, said Valente Alvarez, a food scientist and director of the Food Industries Center at Ohio State University.
The food-processing method is one of the oldest there is. Archaeologists have found evidence of a fermented alcoholic drink — a fruit, rice and honey concoction — dating to 7000 B.C. in China. Sailors staved off scurvy by scarfing down vitamin-rich sauerkraut packaged in casks to last for years, Alvarez said.
“It’s existed as long as humans have existed,” he said of fermentation.
What is fermentation?
If you’ve ever eaten soy sauce, summer sausage, yogurt, kombucha, sauerkraut or vinegar, you have already sampled a variety of fermented foods.
Zymology, the science of fermentation, harnesses microorganisms to convert carbohydrates into alcohols or acids.
Take milk, for example. On its own, milk has a mild, sweet flavor. When it's fermented, bacteria convert lactose, a milk sugar, into acid, producing cheese or yogurt with a tangy, sour taste.
Another type of fermentation — one that transforms sugar into ethanol — produces wine, beer, ciders and some spirits.
Fermentation also includes the process by which bread is leavened when yeast converts sugar into carbon dioxide.
“Fermentation can occur in any food,” Alvarez said. “The only commonality is the distinct acid flavor that all fermented products have.”
He emphasized that the process is distinct from both pickling (which involves preserving in acetic acid) and curing (which uses salt or sugar to draw the moisture out of a food such as prosciutto).
How does fermented food differ from rotten food?

Bacteria have an unpleasant reputation, Alvarez said, but fermented foods exemplify the sterling variety.
“People don’t realize fermented food has good bacteria," he said. "We see all bacteria as bad, but the only bad ones are pathogens."
Fermented foods are more acidic, which can actually inhibit the growth of pathogens such as E. coli, salmonella and listeria.
Research shows that fermented foods can have enhanced nutritional properties and that the living microorganisms they contain function similarly to probiotics, which are good for the digestive system.
How can I sample it?

Fermentation expresses itself differently across cultures, so trying unfamiliar cuisines probably will introduce you to different fermented products.
Kefir (a milk product) has spread from its Russian and central Asian origins. Miso (a soybean paste) is a staple in Japanese seasoning. Dosas (pancakes) hail from India, skyr (a soft cheese) from Iceland and chorizo (pork sausage) from Spain and Portugal.
You also can ferment foods at home. Zala ferments a variety, from cabbage and carrots to spaghetti squash, turnips, tofu, teas, beets, green tomatoes and hot peppers.
She recommends playing with flavors by tossing in bonus ingredients such as grape leaves, turmeric, garlic, ginger and spices. Fermentation is best approached as an experiment, she said.
“This is a live food. It’s living; it’s changing. It’s never going to be exactly how you imagine.”
The only constant for Zala is her concerted effort to label the exact ingredients and start date for every batch, to help her track what worked and what didn’t. Beyond that, she said, the process is all play.
“Homogenization is boring," she said. "You always know what you're going to get at the grocery store or ordering fast food."
Fermentation, on the other hand, promises an element of surprise, she said: "You’re taking back that creativity.”


DO-IT-YOURSELF FERMENTATION
4-6 cups chopped vegetable of choice (cabbage, carrots and onions work well)
about 1 gallon water (unchlorinated)
salt (not iodized, preferably sea salt)
canning jars
plastic sandwich bags

Chop vegetables, to your liking, into chunks, slices, strips or coins.
Using a fist, pack them down into a canning jar.
In a separate bowl, make the brine with a ratio of 4 cups water to 2½ tablespoons salt.
Pour brine into jar until water level rises above the vegetables. Fill a plastic bag, one per canning jar, with tap water and use to pack the rest of the jar. The bag should act as a weight to keep the vegetables from floating to the brine’s surface, and push out any air from the jar.
Put the jars on a tray, as they will leak water as they ferment.
Leave at room temperature and begin tasting the mixture after a week. Continue fermenting until desired taste is reached, then refrigerate and enjoy. Ferments will stay safe and tasty in the refrigerator for months, even years.
— Marion Renault explores the science of food in her monthly Matters of Taste column for The Columbus (Ohio) Dispatch. She can be reached at mrenault@dispatch.com or follow @MarionRenault on Twitter.