We need technological help to grow tempeh in places where the climate is not suitable for its growth. The idea of our fermenter is to replicate the Indonesian climate, to cooperate with nature and help it to help us. But the technology for our device doesn’t need to be intrusive, connected to the internet, track our habits or consume more energy than it actually needs. It just needs to produce heat according to what the growth of the mycelium requires. Only a few components are needed. A few components that we can understand, repair and improve if necessary. A few components that reconcile open-source technology with citizens and our food production. We like to call it calm technology.