Several years ago, judges at a beer competition in Peru noticed that many entries in the IPA category lacked the level of bitterness they expected. Talking to brewers who made those beers, the judges learned that many of those IPAs were brewed at higher altitudes.
The brewers hadn’t adjusted their recipes to compensate for reduced isomerization at lower boiling temperatures.
Recently, Roadhouse Brewing in Jackson Hole, Wyoming, collaborated on a series of Kush IPAs with multiple breweries. The fifth brewery to participate—Half Acre in Chicago—was the first “to ask me about altitude,” says Roadhouse brewmaster Max Shafer. Jackson Hole is 6,200 feet (1,890 meters) above sea level.