popular type of tempeh is produced from soya beans and is also known as
tempeh kedele. The process of tempeh production is outlined in Figure
9.17. Whole clean soya beans are soaked overnight in water to hydrate
the beans. A bacterial fermentation occurs during this stage decreasing
the pH to 4.5–5.3. The hydrated beans are dehulled and the moist
cotyledons cooked; a process which pasteurizes the substrate, destroys
the trypsin inhibitor and lectins contained in the bean and releases some
of the nutrients required for fungal growth. After cooking, the beans are
drained and may be pressed lightly to remove excess moisture before
spreading into shallow bamboo trays and allowing to cool. Starter culture
is added either by mixing some tempeh in with the cooked soya beans
prior to packing in the trays or by sprinkling a spore inoculum, prepared
by extended incubation of a piece of tempeh, on to the beans.
The fermentation is invariably a mixed culture of moulds, yeasts and
bacteria but the most important component appears to be Rhizopus
Figure 9.17 Tempeh production
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