Much instruction on the Internet describes how to make tempeh from a starter kit or spores. I have not found one which describes making tempeh from existing tempeh. It seems illogical to make tempeh from spores all the time; how did they make tempeh before the Internet?

Ingredients

Soya beans 300g
Vinegar 4 tablespoon
Tempeh 50-100g

Instructions

1. Soak soya beans for 8-12 hours
2. Once soaked for at least 8 hours, dehull and split beans in to half by kneading the beans and rubbing the beans between hands. Do so until about 90% of the beans are dehulled.
3. In between dehulling the beans, wash off excessive hull by pouring the excess water away and adding fresh water.
4. Boil 2 litre of water in a pot with a lid and add 3 tablespoon of vinegar.
5. Add dehulled beans in to boiling water and boil for 30 minutes. Watch out for overflow.
6. Once boiled for 30 minutes, drain as much water as possible.
7. Turn fire to a low heat and stir beans until relatively dry. This is to allow excess water to evaporate. Dry is defined as no water transfer if touched. Should feel like a damp cloth.
8. Add 1 tablespoon of vinegar in to dry beans and mix.
9. Leave to cool in pot until almost room temperature. Less than body tempreture.
10. Use existing tempeh and break them down to small pieces.
11. Add the tempeh in to the beans.

Fermentation

1. Using a safety pin or a paper clip, perforate 2 20×20 cm plastic bag, preferably resealable ones with holes 1 cm apart.
2. Place beans in to plastic bags and flatten with 2 chopping boards.
3. Place in a warm place, between 25-30C for 3 days.
4. The first 24 hours, you should see most of the beans covered with white stuff, and some black patches. The beans will feel warm during this period.

Harvest after 3 days. For basic preperation, cut pieces in to 1 inch square, season with salt and tumeric and fry until golden brown.