Hey everyone!! So a friend and I have started making tempeh and just distributing it small-scale to a couple friends. The last couple of batches have some black spots and I was wondering if anyone could help us figure out why.

Tempeh procedure Last batch - 3 types -soy and black chickpeas, red beans, and black beans

First soak all beans - 12 hours - dehull soy - cook until al dente - dry and split - split 70% of beans

Add starter (1/3 tsp - 350 g batch)

Placed tightly in small plastic bags with holes placed using a toothpick. We also tried with a silicon molf for the first time. Does anyone have any recommendations on how to cover the mold? We used plastic wrap but I'd rather not.

Placed the tempeh in the center rack of oven on top of bamboo sheet - heat with oven light at top and lamp at bottom that turns off at 29 degrees and back on at 27 C

Tempeh keeps coming with black spots. This time the temperature was quite stable.

Thank you so much in advance! I truly appreciate any and all help