Tempeh is a traditional Indonesian soy product that is unique because it is fermented with a whole-bean process. Unlike tofu, which is made from soy milk, tempeh uses whole soybeans that are inoculated with the mold *Rhizopus oligosporus*. As the mold grows, it produces white filaments called hyphae that knit the beans together into a solid cake. This fermentation process lasts about 24 to 36 hours at a warm temperature ($30-35$°C). The mold also produces enzymes that break down the proteins and fats, making the nutrients more bioavailable and creating a nutty, mushroom-like flavor. Tempeh is highly valued as a meat substitute because of its high protein content and firm texture.