That picture to the right is the finest batch of Koji you’ll ever see. I jest but it does look good (if you like fungus). One of my friends is an excellent cook and has recently marched into the unknown depths of fermentation. Swept up by the excitement of experimenting and creating new flavours he asked me to help make a temperature and humidity controlled chamber. I have worked on it on and off for several months with my last design up and running since September. The versions before worked but either broke or had other problems and were upgraded. I hope this current design holds up until I have time to work on it again. 

The main unit is a thermal box with a tray in it for the Koji. The controller has two sensors, a temperature probe that sits in the grain and a fancy temperature/ humidity probe attached to the inner wall of the box. To maintain the right conditions there is heating mat (used for reptiles apparently) and a usb humidifier. There is an LCD to display information and two pots control allow the user to set the temperature and humidity. 

I recently discovered how cheap touch screens are. $5.00?? How can a touch screen possibly be that cheap, its ludicrous! I have started messing around with a generic menu screen library for Arduino I found somewhere on github (I will add the link when I find it), and plan to add it to the design. No knobs required for changing the temperature/humidity and I plan on adding user programs on it so that a 3 day Koji cycle can be set and run without having to check and change the temperature everyday.