As tempeh comes from Indonesia, the tropical wheater have made the mold of tempeh easy to grow on local soybeans. If you don’t live in a tropical country, the biggest technical challenge to grow tempeh is to simulate those condition in a dedicated chamber. With some basic insight and a little creative ingenuity you can set it up without too many effort.
The level of humidity and the level of oxygen will be maintained by its container. Indeed, you will need an airtight container with small holes to make your tempeh. This point is explained in the tempeh moulds section. The main challenge is more to control the heat.
Set up your DIY solution
When we lived in Amsterdam we managed to make our first tempeh in an oven with only the light on to reach a temperature of about 30°C. Indeed, kitchen ovens are insulated enclosures that can be adapted for this purpose. You can place a thermometer inside your oven to monitor the temperature and turn off the light when it reaches the right temperature. But not all ovens have a light that can be turned on independently of the oven itself.
In a second phase, we installed a shelf next to our boiler which had its own room where the temperature was always around 27°C. But when we moved, we had to find another solution because our boiler was no longer in the flat. So we decided to design and build our own open-source fermenter-lab. You are more than welcome to read its documentation and create your own version.
the Domingo Fermenter
Since then, we’ve spent some time reiterating our design in a simple kitchen appliance to allow anyone to ferment their own tempeh at home. It will be soon available!
We also had the crazy idea of using our body heat to ferment tempeh. We made a necklace out of it, check it out.