Bread: Sourdough and other fermented breads use packaged or wild ambient yeasts to give them leavening and flavor. Many artisan breads are fermented but not called sourdough, so ask if you are interested. All the yeasts are deactivated by baking. For a fermented bread treat, look for injera, an Ethiopian flatbread, at Ethiopian restaurants and some co-ops.
Chocolate: Whole cacao beans are fermented before being made into chocolate. The process removes some bitter tannins and adds complexity to the finished chocolate. The cacao is cooked, so no active cultures remain.
Dairy: Yogurt is made of milk or nondairy milk that is seeded with a bacterial culture and allowed to ferment, then chilled to slow the live bacteria (probiotics). There are many types of yogurt, from thick Greek yogurt to Icelandic skyr to fruity cups of mild American-style yogurt. It's widely available. Kefir is like yogurt, but made with a different culture. It's less thick than yogurt and is usually poured over cereal or into smoothies or enjoyed as a drink. Find it next to the yogurt at the grocery store.
Hot sauce: Some hot sauces are fermented to bring out more interesting tastes, such as Tabasco, Korean gochujang and Sriracha. They are widely available. Kombucha: A carbonated beverage made from tea that comes in many flavors, which can be sipped on its own or mixed with juices in cocktails, dressings or smoothies. Most groceries and co-ops stock them with the single bottles of cold drinks.
Kraut: Raw kraut is made by simply salting shredded cabbage and waiting for the lactobacteria to do their work. You will find it in the refrigerated section, unlike pasteurized kraut, which has been boiled to kill the lactobacteria. You should be able to get fermented kraut in your grocery store, co-op or many farmers markets. There are many versions of fermented cabbage, originating in countries all over the world, with various vegetables and seasonings added. You might find Korean kimchi in your grocery or co-op. Japanese tsukemono and Chinese salted cabbage (span ka) are found in Asian markets and restaurants. Check your farmers market for a local producer making specialties such as South American curtido and other fermented vegetables.
Miso: This is a salty paste made from salted and fermented soy and other beans and grains. It has some active cultures. Soy sauce and fish sauce are fermented, then pasteurized to kill the bacteria. All three are available in many grocery stores, co-ops and Asian markets.
Olives: The Greek style of olive preservation is to ferment the olives in salt. Oil-cured olives are fermented in oil. Other styles are not fermented and usually are processed with lye. Look for fermented olives in the cold case at your grocery or co-op.
Pickles: Refrigerated cucumber pickles are sometimes lacto-fermented, but most are simply cooked in a vinegar bath. The label should say, and fermented are worth seeking out for their crisp texture and extra flavor.
Tempeh: This is a fermented food, usually made with soybeans, often with other beans and grains mixed in. Fermentation makes it more digestible and gives it a meaty quality. Try marinated and baked tempeh added to sandwiches, stir fries or salads. Available in many grocery stores and co-ops.