Tempeh

Tempeh (Indonesian: tempe) is a fermented food made from cooked soybeans that have been inoculated with a mould of the genus Rhizopus. During fermentation, the mould grows a dense web of white filaments (mycelium) that binds the beans into a firm cake. Tempeh originated on the island of Java in Indonesia, where it remains an inexpensive, everyday protein food. It is widely used in vegan and vegetarian cooking because of its firm texture, nutty flavour and high protein content.

History

Tempeh is native to Java. Its exact origins are unknown, but it has been part of Javanese cuisine for at least several centuries, and it is mentioned in the Serat Centhini, a Javanese literary work compiled in the early 19th century. Unlike tofu, which arrived in Indonesia with Chinese communities, tempeh is regarded as an indigenous Indonesian invention.

Tempeh became known in the Netherlands through colonial and migration links with Indonesia, and spread more widely in Europe and North America during the second half of the 20th century, particularly through the natural foods and vegetarian movements.

Production

Traditional and commercial tempeh production follow broadly the same steps:

1. Soaking and dehulling – soybeans are soaked, and their hulls are removed.
2. Partial cooking – the beans are boiled, drained and dried on the surface.
3. Acidification – some methods include a mild acid (such as vinegar) or a short soak that lowers pH, which helps discourage unwanted bacteria.
4. Inoculation – a starter culture containing spores of Rhizopus oligosporus or Rhizopus oryzae is mixed in.
5. Incubation – the beans are packed into perforated bags, trays or, traditionally, banana leaves, and kept warm (around 30 °C) for roughly 24–48 hours.
6. Finishing – once a firm white cake has formed, the tempeh is cooled, and is usually pasteurised or refrigerated to stop fermentation.

Black or grey patches on tempeh can be a normal result of spore formation, but slimy texture, pink or other unusual colours, or a strong ammonia smell indicate spoilage.

Variations

Although soybeans are the classic base, tempeh can be made from other legumes and grains, including chickpeas, black beans, lentils, barley and rice, either alone or mixed with soy. In Indonesia, related fermented products are also made from by-products such as okara (soy pulp), known as tempe gembus.

Culinary uses

Tempeh is almost always cooked before eating. Its flavour is often described as nutty or mushroom-like, and some people find it slightly bitter; steaming or simmering it for around 10 minutes before further cooking is a common way to mellow the taste and help it absorb marinades.

Common preparations include:

• Tempe goreng – sliced, marinated and deep-fried, a standard Indonesian side dish.
• Tempe mendoan – thin slices dipped in a seasoned batter and briefly fried.
• Tempe orek or kering tempe – tempeh fried and coated in a sweet-spicy soy sauce glaze.
• Crumbled into sauces, chilli or tacos as a minced-meat substitute.
• Sliced and smoked or marinated as "tempeh bacon" in sandwiches.
• Cubed in curries, stir-fries and grain bowls.

Nutrition

Because whole beans are used, tempeh is generally higher in protein and fibre than tofu. Soy tempeh typically contains around 18–20 g of protein per 100 g, though values vary by product. It also provides iron, magnesium, manganese and some calcium.

Fermentation partially breaks down some compounds in soybeans, which some people find makes tempeh easier to digest than unfermented beans. It is sometimes claimed that tempeh is a source of vitamin b12; however, any B12 present comes from bacterial contamination during production rather than from the mould itself, and amounts are inconsistent. Commercial tempeh made under hygienic conditions should not be relied upon as a B12 source, and vegans are advised to use fortified foods or supplements instead.

Storage

Fresh tempeh is perishable and is usually kept refrigerated for up to about a week or frozen for longer storage. Pasteurised, vacuum-packed tempeh has a longer shelf life.

See also

• tofu
• seitan
• protein
• vegan on a budget
• meal planning