Before all your fancy, high-tech cylindroconical fermenters, beer was brewed with traditional open-air fermenting tanks. The brand of Anchor Steam beer is actually an allusion to that steam beer of the 1800s (open fermented on the tops of buildings, steaming in the morning). Obviously, most breweries today use closed cylindroconical fermenters because they can make larger batches of beer and the fermenters are easier to clean, but those advanced engineered fermenting tanks don’t necessarily make better beers.
So when the folks at Anchor Brewing Co. and D.L. Geary Brewing Co. employ open fermentation operations, it’s not just for its cool traditions (though that’s part of it). The technique does have its unique attractions and advantages — like enhancing those beautifully fruity ester notes and creating crazy long yeast generations. Disadvantages include cleanliness and the need for a secondary fermentation vessel, but many craft breweries feel it’s well worth the trouble. Learn more about open fermentation in this awesome Q&A here. Then watch the video above. It’s a six-day. time-lapse video of the open fermentation of Sierra Nevada Brewing Co.’s Bigfoot Barleywine Style Ale, scored to Edvard Grieg’s “In the Hall of The Mountain King,” which makes everything instantly awesome.