Think what you will of the Granite City brewpub chain, my trip to their worthouse in Ellsworth, Iowa was one of the most fascinating brewery visits I have ever done. If you have driven along I-35 between Ames and the Minnesota state line, then you have passed by the brewery and probably didn’t know it. A small grain silo on the side of the building is the only thing that even remotely identifies it as a brewery. It’s a tiny, non-descript place in a tiny, non-descript town, but it supplies unfermented wort to 26+ stores in several states.

Granite City’s “fermentus interuptus” method of transporting unfermented wort to the locations for fermentation on site has advantages in terms of efficiencies of scale and consistency of product. But for anyone who knows about the brewing process, it’s a cringe-worthy proposition. Wort is an ideal growth medium for all sorts of beer-spoiling bugs. Brewmaster Cory O’Neel is the man to manage the situation. His background is in brewery quality control. Once he came on board at Granite City he instituted a set of strict protocols intended to head off problems. He built a lab at the worthouse (actually the lab was already there he told me, but it was mostly being used to heat up pizza). Wort is tested numerous times along its journey. Yeast is propagated in house in a sterile yeast lab. Fascinating stuff about an interesting way to brew.