Tempeh help

[AlienSkyler]

i used to make tempeh, i guess just soy free, a few years ago i built an incubator out of a styrofoam cooler, a seedling heat mat, and a temperature controller for the heat mat. i also poked knitting needles through the styrofoam cooler to make a rack for the tempeh to sit on
basically, when i lived with my mom i was able to make decent tempeh, not every batch was good but i ate a lot of tempeh. i kept the incubator in the garage, i don't know if that makes a difference.
when i moved to an apartment i only attempted making tempeh a couple times but it never worked. i do think those times i overcooked the beans.
but i moved to a house and have more space and wanted to start making tempeh again, and every single time it has not turned out, and i can't figure out what is wrong
i realized the incubator was contaminated with gross liquid from a bad batch and thought if i replaced the styrofoam and cleaned off the seedling mat really well it would work
still didn't work
i thought maybe my tempeh starter had expired and ordered a different brand of spores
still didn't work, though i saw enough mycelium growth to confirm the spores are active and something else was interfering with it
i get this vibe that something is wrong with the temperature or humidity levels but i did an experiment where i plugged in the incubator and put a little cup of water in and then made sure the temperature of the water was the same as what the probe said, and it was, i thought something was wrong with the temperature controller
the temperature controller somehow lost the ability to be set to a different temperature but it still worked since it got stuck on the right temperature for tempeh and koji
i am at a complete loss as to what is wrong and i miss having tempeh and want to fix this problem
the incubator smells like bad tempeh again and i don't know if i need to decontaminate it or how (i did line it with a black garbage bag to avoid replacing the styrofoam if it got contaminated again and i don't know if that caused a problem with the temperature)
the last batch had the temperature displayed too low, like 78 degrees Fahrenheit, but it still went bad the same way

[KEALA]

Hello,
You wrote:

the incubator smells like bad tempeh again and i don't know if i need to decontaminate it or how

You ought to make sure that your gear (and yourself) is as clean as possible.
Bad smell is likely indicating spoilage of bacterial origin.
There might be an issue with the humidity level in your incubator (I meant condensation).
You also wrote:

i did line it with a black garbage bag to avoid replacing the styrofoam if it got contaminated again

You do not mention any air intake in your incubator.
Traditional tempeh is produced via an aerobic fermentation. Aeration and heat removal are both essential in production of good tempeh.
Have a good day.
A-

[ArthurDent004]

I find making Tempeh is all about your process so if you can outline that from start to finish we could help more. From what you said so far I'd start with sanitizing all your equipment and removing the liner from your Styrofoam cooler. If you are looking for a cooler that is more durable I believe I have posted pictures of the incubator I made out of a party cooler. Check out my other posts to see what I've made.