Soy is a plant protein made from soybeans that is used to create a range of soy-based food products, including tofu, soymilk, and soy cheese. Some soy products are fermented to improve digestibility, make isoflavones more readily available, and increase the already powerful nutritional pluses of unfermented soy foods. Among the more familiar fermented soy foods available in the Western world are tamari, or soy sauce, miso, and tempeh. Fermented soy milk, powder, soybeans, and a wealth of other foods that have been eaten for centuries in Asia are becoming increasingly available in the West.
The fermentation process frees up soy’s phytoestrogens so they can be more readily absorbed. These antioxidant isoflavones are thought to reduce inflammation throughout the body as well as to fight cancer. Fermented soybean foods help digestive health by introducing probiotic bacteria to the intestines. Yet another boost that fermentation gives soy foods is a greater cholesterol-fighting ability.
Fermentation of soybeans can be accomplished in a number of ways. Most commonly, specific bacteria or mold are cultured and added either before or as the food is processed. Some home cooks create their own fermented soy foods, such as natto, by following a few simple steps.
As the enhanced nutritional benefits and unique flavors and textures are the result of soybean fermentation, more and more health-conscious consumers are seeking out fermented soymilk, soy yogurt, powders, and soy meat substitutes. Many shoppers are familiar with tofu and soymilk. Fewer, however, have tried natto, tempeh, or other less common fermented soy foods.
Tempeh, a dense fermented bean cake, is heartier in taste than its blander cousin tofu. Like meat, it can be fried on the stovetop, boiled in broth or water, or baked in the oven. Tempeh’s flavor is strong; those who like it describe it as tasting like meat cooked with mushrooms.
Fermented bean paste, also called miso, can be purchased at most health food groceries and increasingly in mainstream grocery stores as well. Adding miso to heated vegetable broth for a simple soup or spreading it on bread to add moisture and flavor to sandwiches provides health and taste benefits with few calories. Many cooks habitually combine a little miso into sauces, marinades, and hot or cold dressings for salads and vegetables.
Other popular choices among individuals who eat soy for its health benefits include fermented soymilk and soy yogurt because they cannot digest milk products. These dairy substitutes contain enzymes that have broken down soy sugars to enhance their digestibility. Another way to introduce fermented soy to the diet is through soy sauces such as tamari or shoyu, which can be sprinkled on rice or other grains, as well as on meat and meat substitutes, to zing up the flavor.