A quick primer is in order: when it comes to hobby brewing there’s two main types, extract brewing and all-grain brewing. The former uses a syrup that has been extracted from the grains at a factory while the latter adds the steps to do this yourself. But in both cases the brewing grains have already been malted. This is a careful process of soaking the grains and then kiln drying them. [Richard Oliver] built his own malt kiln controller to add the preliminary step to his home brewing ritual. Now the only thing he’s not doing himself is growing the grains (and perhaps culturing the yeast).

His original design used a food dehydrator for the drying step, but this didn’t work because the temperature wasn’t at the correct level. The new build uses the ceramic heating element from a 300W hot air gun. A blower directs air through the element and into the wooden box that serves as the kiln. An Arduino monitors the heated air to keep it right in the sweet spot. He’s included a graphing GUI for easy monitoring, which is shown in the video after the break.