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Tempeh
A Fermented, Plant-Based Meat Alternative
By Carrie Dennett, MPH, RDN, CD
Interest in plant-based eating already was on the rise before the coronavirus pandemic, but in recent months, demand for meat alternatives has increased, whether due to perceived healthfulness or periodic meat shortages. For consumers who don’t want to go the “faux meat” route, traditional soyfoods such as tofu or tempeh may be more appealing.
Tempeh is a traditional Indonesian soy product made from fermented soybeans. It has a firm texture and an earthy, nutty, slightly yeasty flavor, which becomes more pronounced as it ages. Like tofu, tempeh is made from soybeans—sometimes with whole grains such as brown rice, barley, oats, and millet—but unlike tofu, tempeh is a whole soybean product with different nutritional characteristics and textural qualities. Tempeh’s fermentation process, and the fact that the whole bean is retained, gives it a higher content of protein, fiber, and nutrients than tofu.1,2
Tempeh originated on the Indonesian island of Java—unique, since most soyfoods originated in China, Japan, or Korea. The exact origins of tempeh are less clear than that of other soyfoods, but it’s thought that tempeh has been around for at least several hundred years, even though the earliest known reference to it was in 1875. Tempeh may have been accidentally produced as the byproduct of tofu production, when discarded soybeans interacted with fungal spores. The first commercial production of tempeh in the United States, by Indonesian immigrants, was in 1961.2
How Is Tempeh Made?
Tempeh is made through a natural culturing and controlled fermentation process that binds soybeans into a cake form. Tempeh starter cultures typically include multiple Rhizopus species of fungus, but R oligosporus is predominant. R oligosporus is the preferred starter because it grows effectively in the warm temperatures typically found in Indonesia. It has strong enzymatic activity, and it produces metabolites that can inhibit and outcompete other molds and pathogenic bacteria.1
In his book, The Art of Fermentation, Sandor Katz wrote that fresh tempeh is “vastly superior to what’s typically available commercially,” and indeed it’s possible to make tempeh at home using a purchased starter. Although the exact process has some variations, whether tempeh is made at home or commercially, the four major steps in production are soaking, boiling, inoculating, and incubating. First, soybeans—and grains, if used—are soaked for up to 24 hours in room temperature water, resulting in an initial fermentation by lactic acid bacteria. This helps prevent growth of any undesirable bacteria that may spoil the tempeh. Then, the outer covering of the soybean is removed and the beans are cooked until they’re just soft enough to bite through. Finally, they’re inoculated with the starter and fermented again at a temperature of 85° to 90° F under perforated plastic covers for one to two days.1
After fermentation, the mycelia—the vegetative, threadlike portions of a fungus—of R oligosporus multiply, ultimately growing dense enough to compress the soybeans into tempeh’s characteristic firm, compact “cake” form. Good quality tempeh will have a white coating from the mycelia, as well as dark spots formed by fungal spores. The more spores produced, the stronger the aroma and flavor. Once the soybeans are bound together, the fungus releases protein-digesting enzymes, which contribute to a pleasing texture, flavor, and aroma—sometimes compared to that of a chewy mushroom.1
Tempeh in the Kitchen
Because its protein content is similar to that of meat, tempeh often is used as a meat substitute. In Indonesia, tempeh usually is cut into thin strips and fried, cubed, and incorporated into coconut milk curries, or barbecued in sweet sauces. Marinating tempeh in a sweet-salty-sour sauce before cooking also is common. Tempeh can be sliced, cubed, or crumbled, and included in stir-frys, chilis, or pasta sauces.
Marinated Baked Tempeh
Serves 4
Ingredients
1 8-oz package plain tempeh, cubed
2 T tamari or soy sauce
2 T rice vinegar (can substitute cider or white wine vinegar)
1 T toasted sesame oil
1/2-1 tsp sriracha
1/2 tsp honey
1-2 cloves garlic, minced
Directions
1. Place the tempeh cubes in a shallow dish. Combine the tamari, vinegar, sesame oil, sriracha, honey, and minced garlic in a small bowl and whisk to combine. Pour mixture over the tempeh. Marinate at room temperature, turning occasionally, for 30 minutes to 1 hour. (Can also be marinated in the refrigerator for up to two days.)
2. Preheat oven to 400° F and line a baking sheet with parchment paper. Arrange the tempeh cubes on the baking sheet, reserving the excess marinade.
3. Bake for 10 minutes, then flip the cubes and brush with some of the reserved marinade. Bake about 10 more minutes or until the cubes are golden and crisp around the edges.
4. Enjoy on salads or grain bowls, in wraps or sandwiches, or as part of a component plate or vegetable stir-fry.
Nutrient Analysis per serving
Calories: 150; Total fat: 9 g; Sat fat: 2 g; Cholesterol: 0 g; Sodium: 476 mg; Total carbohydrate: 7 g; Dietary fiber: 0 g; Sugars: 1 g; Protein: 11 g
Source: Recipe courtesy of Carrie Dennett, MPH, RDN, CD
— Carrie Dennett, MPH, RDN, CD, is the nutrition columnist for The Seattle Times, owner of Nutrition By Carrie, and author of Healthy for Your Life: A Holistic Guide to Optimal Wellness.
References
1. Shurtleff W, Aoyagi A. History of tempeh. SoyInfo Center website. https://www.soyinfocenter.com/HSS/tempeh1.php
2. Katz SE. The Art of Fermentation. White River Junction, VT: Chelsea Green Publishing; 2012:284-296.