Kimchi and kraut are taking up space in the dairy case, and kombucha and probiotic drink flavors are starting to crowd out the sodas in the drinks cooler. The yogurt section has expanded to include kefir, skyr and even non-dairy yogurts. Restaurant chefs are garnishing plates with tangy and colorful pickled vegetables, and Minneapolis now has a restaurant, Gyst Fermentation Bar, dedicated to serving those very foods.

While fermenting may be trending, it's one of the oldest methods of food preservation. Long before refrigeration, humans learned that certain foods actually improved, instead of spoiling, when left to their own devices. Honey, mixed with water, turned to wine. Beer, wine and even hard cider came about from letting bacteria and yeasts have their way with grain, grapes and apples. Many of our favorite foods are fermented, including chocolate, tea, cheese, vinegar, miso, soy sauce and sourdough breads.

Fermentation is simply the act of allowing bacteria and yeasts to colonize a food in a controlled environment. This can be done with cultures, such as the yogurt cultures or packaged yeasts you can buy, or it can be done by allowing the wild, ambient yeasts that surround us to take up residence. In some foods, the microbes do their work, and when we have achieved what we want with them, we kill them off by heating them, as we do with a loaf of bread. Those foods are differentiated from the live-culture fermented foods, such as kimchi and yogurt, which simply slow down their bacterial activity in refrigeration, but deliver live populations of bacteria with every bite or sip.

Nate Uri, master brewer at Prohibition Kombucha in the Twin Cities, makes the fermented drink made from tea, that is then sold on tap or in bottles around the region (for a list of where it is available, see www.prohibitionkombucha.com). He became interested in kombucha while living in Portland, Ore., in 2012. "It blew me away: delicious, fresh, refreshing. It was a great substitute for a cocktail," he said. In 2013 he brought West Coast-style kombucha on tap to the Twin Cities.

You can find his kombucha at Gyst Fermentation Bar (25 E. 26th St., Mpls., 612-758-0113), where Jim Bovina keeps tabs on crocks and jars as they transform into tangy treasure.

"We keep our ferments pretty light, nothing too funky. I make small batches based on what is good right now, and I don't want to have the same things all the time," said Bovina, Gyst's food and fermentation specialist.

Adrienne Logsdon of Kiss My Cabbage makes unique fermented foods to sell at the Mill City and Linden Hills farmers markets. Her entry into the world of kimchi, kraut and curtido was quite by accident, after having a bumper crop of cabbage and a partner who suggested that they experiment with sauerkraut.

The book "Wild Fermentation," by Sandor Katz, influenced her. "I started playing around with it, and I was seeing health benefits myself from eating the foods. I thought, we all need to eat this, why isn't it everywhere, like eggs and butter?"

Whether you are new to live cultured foods or a longtime convert, give some of these exciting new foods a try. If kraut is not your thing, maybe kombucha, kefir or kimchi will please your palate. Or do what these others do: Add the fermented food to other dishes.

• Logsdon of Kiss My Cabbage puts curtido on masa corn cakes fried in butter with melted Cheddar cheese on top. She also does her morning eggs with kimchi or curry kimchi.

• At Gyst, kraut goes in the grilled cheese sandwich; peanut butter sandwiches get kimchi.

• Nate Uri of Prohibition Kombucha suggests the kombucha mimosa: Pour 2 ounces of your favorite kombucha (Ginger Vesper is particularly good, he said) and top the glass with Prosecco.

Robin Asbell has written six cookbooks, including "The New Whole Grains Cookbook" and "Gluten-Free Pasta." She teaches cooking in the Twin Cities.