Tempeh is a unique food product made from fermented soybeans, and its production involves a fascinating blend of traditional and modern techniques. This article explores the process of making tempeh, highlighting both traditional methods and contemporary innovations.
Traditional Methods
The traditional method of making tempeh begins with whole soybeans, which are soaked, dehulled, and partly cooked. In Indonesia, tempeh is often produced using Hibiscus tiliaceus leaves,
which naturally harbor the mold Rhizopus oligosporus. The soybeans are pressed into the leaf, and fermentation occurs, resulting in tempeh.
The principal step in making tempeh is the fermentation of soybeans, which undergo inoculation with Rhizopus spp. molds. The beans are spread into a thin layer and allowed to ferment for 24 to 36 hours at a temperature around 30°C. During fermentation, the soybeans are bound into a solid mass by the mycelium, forming a compact cake.
Modern Innovations
Modern tempeh production often uses commercial starters containing Rhizopus oligosporus or Rhizopus oryzae. These starters ensure consistent fermentation and quality. The use of sealed polyethylene bags has become common, allowing for better control of fermentation conditions.
During the fermentation process, optimal time, temperature, oxygen, humidity, and pH levels are required to encourage the growth of the Rhizopus mold while discouraging undesired microorganisms. The pH level is maintained around 3-5 by adding mild acids like vinegar, lactic acid, or acetic acid.
Quality and Packaging
Once tempeh is produced, it is categorized based on its quality: good, unfinished, and inedible. Good tempeh includes beans bound into a firm, compact cake by a dense, uniform, white mycelium. Proper packaging is crucial for maintaining tempeh's quality and extending its shelf life.
Tempeh is traditionally wrapped in banana leaves, but food-grade wrapping paper and perforated polyethylene bags are now commonly used. These materials help retain the quality of tempeh and extend its shelf life. Tempeh is a perishable food and must be refrigerated or frozen immediately after processing.
The evolution of tempeh production reflects a balance between preserving traditional methods and embracing modern innovations. As tempeh continues to gain popularity worldwide, its production methods will likely continue to evolve, ensuring consistent quality and accessibility.
