Rhizopus molds

Industrial tempeh is made with certain edible strains of Rhizopus oryzae or Rhizopus oligosporus. In Indonesia, where tempeh originated, homemade tempeh usually contains a mixture of both Rhizopus oryzae and Rhizopus oligosporus strains, along with other bacteria. They make tempeh starter by incubating cooked soybeans in hibiscus leaves.
Below are some microscopic pictures of the Rhizopus oryzae strains used in our tempeh starter..

rhyzopus oryzae mycelium
Rhyzopus oryzae grown on agar.

picture of rhyzopus oryzae mycelium
Mycelium of Rhyzopus oryzae on fresh tempeh.

picture of rhyzopus oryzae sporangia
Sporangia of Rhyzopus oryzae on overripe tempeh.