Mash Vat

Mash pours into the fermenting vat. Once full, it starts to bubble with CO2 as the sugars in the grain are converted to alcohol and CO2. In fact, the CO2 lies so heavily over the vats that anyone falling in would die before reaching the side. I had thought they cooked the mash but in fact the special yeast cultures don't work well at higher temperatures and those are cooling tubes seen at the bottom of the vat.