It is mostly made from fermented yellow soybeans, but it can be made from other legumes (such as wing beans, pigeon beans or velvet beans), or grains. Tempe made from soybean is considered the best quality.
The soybeans are cooked and cooled, then a starter culture is added to them, and the mixture is packed into banana leaves. It is then allowed to mature like a cheese. White mould grows all over and through the beans. One of the main micro-organisms at work is “Rhizopus oligosporus.”
Though Tempe is normally considered Japanese, it’s also very popular in Indonesia, where it is one of the top two fermented foods (the other being their version of soy sauce called “kecap.”) Indonesians consume all that they produce, and don’t export any. It is particularly popular with the Javanese (sic, not Japanese) in Indonesia. Tempe made in Malang, East Java has a particularly good reputation with gourmets.
Many Indonesians consume it as “tempe goreng” — deep-fried, and flavoured with coriander, garlic and salt. “Petchel tempe” is chunks of Tempe simmered in coconut milk. It is also made into crispy chips.
“Tempe Bongkrek” has been banned in Indonesia, as there are hundreds of documented deaths from eating it. It is made from coconut after it’s been pressed for oil. The problem is, it can be contaminated with a bacteria, “Pseudomonas”, that grows in the coconut as it ferments, and produces a toxin called “Bongkrek acid” that interferes with the human respiratory system.
There are many health benefits ascribed to Tempe.
It can be particularly important to vegetarians, as it contains Vitamin B12, normally only available in animal products.
Tempe has been made in Indonesia since at least the 1700s.