A bit of a history lesson first. In 1975, when Anchor Brewing savior and previous owner Fritz Maytag decided to make Liberty Ale, he needed to come up with a method for dry hopping because it wasn’t something that was really being done. Open fermentation was all he and the brewery had known, and late-addition hopping wasn’t an established method outside of some folks doing it in casks.
So he would ferment in the open fermentors and then transfer to closed secondary fermentation where the whole-cone hops would go into a mesh bag. When you do it that way, you see diminishing returns. Obviously, in the ensuing decades, it has evolved quite a bit. There are whole new methods to achieve dry hopping and to get the flavors and aromas that we expect from IPAs into the beer.
We evolved in a lot of ways over the years. When we expanded the brewery a few years ago, we installed conical fermentors, and now we only really do our classics and a few small beers in open fermentation—beers such as Steam Beer, our California lager, and others such as porter, Christmas Ale, and Liberty Ale.
When we released our first IPA, Anchor IPA, we used the open fermentor for the first batch and then moved production to the conical fermentors. Then with our second IPA, Go West, we just used conical fermentors because when you use open fermentation, you’re using two vessels when you really need only one. We were recirculating the beer through hops to impart aromas and flavors, but it wasn’t terribly efficient.
We have been experimenting with our open fermentors on a double IPA, and it’s been interesting. What we’re working on now will be just for our taproom. The beer is quite alcoholic, and because it has experienced that warmer fermentation, it’s still very estery, no matter how much we dry hop it. It’s really coming off more like a strong English ale with hops than a double IPA.
Today’s IPA drinkers believe the style must be excessively hoppy or at least have a lot of hops. It no longer has to be bitter, but the aromatics need to be there. Open fermentation doesn’t help with that. It creates other things that are wonderful but not necessarily what we think about with IPAs.
*(Pictured at top: An open top fermentor at Anchor Brewing in San Francisco.)
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Yeast collecting from an open top fermentor at Russian River Brewing in Windsor, California.