First, find your ‘starter’. As with bread-making and brewing, you can use one batch of tempeh to start the next, but airborne moulds can contaminate your culture and could make the tempeh toxic. Commercial laboratories cultivate pure strains of Rhizopus oligosporus and some will sell small batches, usually in powder form, to home tempeh makers. A few health food shops sell it, or can give you an address for mail order.
To make 8 blocks of tempeh, each weighing about