Following my recent trip to St Austell brewery and having watched several videos about commercial breweries, I'm struck by the difference in speed of completing fermentation. Typically I and several others here will recommend 2 weeks for most beers, though longer for lagers. Commercial brewers with larger systems describe 1 week for ale fermentation, or 2 weeks for lager, though I appreciate there is considerable variation. I appreciate I'll probably find out eventually on the course I'm going to do, but I'm not sure what is the cause of the shorter ferment times? The only thing I can think of is that it is about circulation currents that mix the wort through heat and CO2 activity, which would ensure maximal activity for the yeast for as long as possible, but I'm not sure I'm convinced by this?
Any ideas?
Any ideas?