Tempeh is the only major fermented soybean product that originated outside of China or Japan. It is Javanese — documented in the Serat Centhini (the 12-volume Javanese manuscript from 1814, recording events from the 1600s) as sambal tumpang, a dish made with over-fermented tempeh cooked in coconut milk with spices. The word *tempeh* (or *tempe* in Bahasa Indonesia) likely derives from the Javanese word for the white mycelium mat that binds the soybeans together. The fermentation agent is Rhizopus oligosporus or Rhizopus oryzae — a filamentous fungus that grows naturally on the leaves of hibiscus and teak trees in Java. The traditional starter (*usar*) was a leaf with naturally occurring Rhizopus mycelium — placed between layers of cooked soybeans, the fungus would colonise the beans within 24-48 hours, binding them into a firm cake.
1. **Three-star standard:** Made from whole soybeans with Rhizopus oligosporus. Dense, white mycelium with no discolouration. Firm enough to slice cleanly. Less than 36 hours old (or properly refrigerated). When fried, the exterior is crisp and golden; the interior is nutty and warm. 2. **Professional standard:** Well-made commercial tempeh with dense mycelium. Possibly 2-3 days old (refrigerated). 3. **Competent standard:** Commercial tempeh with some grey spots (early sporulation). Still edible but past its prime. 4. **Failure:** Tempeh with black spots (heavy sporulation), ammoniac smell, or slimy texture. Or, critically, tempeh with pink, orange, or green mould — these indicate contamination with non-Rhizopus organisms and the product is unsafe to eat.
INDONESIAN CUISINE — TIER 1 DEEP EXTRACTION