How to make tempe?
Making tempe is very easy. Here we explain how to make tempe from 100% soy. This is the traditional tempe as it is consumed in the country of origin: Indonesia. To make 500g tempe you need the following ingredients:
- 300 g whole soybeans
- 3 tablespoons vinegar
- 1 teaspoon tempe starter
Tempe starter is made by incubating cooked soybeans in hibiscus leaves, which naturally contains the desired Rhizopus spores, but may also contain contaminating bacteria. Tropical climate is so ideal for tempe production that contaminating bacteria normally cause no problems. In other climates, it is important to make tempe with a good quality tempe starter: it should contain only the desired Rhizopus spores in high quantities and be free of other bacteria.
Step 1: Cracking the soybeans
grain mill The easiest way is to crack the soybeans with a loosely set grain mill. Ideally each soybean is cracked in half.
When buying a grain mill consider that you can also use the dehulled soybeans to make soymilk. If you don't have a grain mill or dehulled soybeans continue with using whole soybeans, you will have to remove the hulls later by hand. If you are lucky, you can find a store that sells dehulled soybeans. Industrial tempe producers normally buy dehulled soybeans. Maybe they will sell you some soybeans!
Step 2: Soaking and dehulling soybeans
Soak the soybeans in 2 liter water for 6 - 18 hours. If you use whole soybeans you should split them by squeezing them with a kneading motion. Stir gently causing the hulls to rise to the surface, then pour off water and hulls into a strainer. Add fresh water and repeat until most hulls are removed. Don't worry if a few hulls remain attached.
Step 3: Cooking the soybeans
Put the beans in a cooking pot and water to cover the soybeans. Add 3 tablespoon vinegar and cook for 30 min. Drain off the water and dry the soybeans by continue heating them in the pot on medium heat for a few minutes and until the beans are dry. Allow the soybeans to cool down to below 35°C.
Step 4: Inoculating the soybeans with tempe starter
Sprinkle the soybeans with 1 teaspoon of tempe starter. Mix with a clean spoon for about 1 minute to distribute the tempe starter evenly. It's very important to mix the tempe starter very well: it reduces the risk for spoilage and the fermentation will be faster.
Step 5: Incubating the beans
Take 2 plastic bags 18 x 28 cm and perforate them with holes at a distance of about 1 cm by a thick but sharp needle. A normal needle is too thin, you need a fat needle or small nail (about 0.6 mm in diameter). This will allow the mould to breathe.
Divide the soybeans in the two bags and seal them. Press them flat, making sure that the total thickness of the beans is max 3 cm. Place the packed beans in an incubator at 30°C or at a warm place for about 36- 48 hours during which the tempe fermentation takes place. Then the container should be filled completely with white mycelium and the entire contents can be lifted out as a whole piece.
Other article of "Production of Tempe, an Indonesia fermented Food" by J.N. Hedger from Department of Botany and Microbiology, University Collage of Wales can be download from here.