In doing a little background research for The Session #80 I came across a 1980 article in the Master Brewers Association of the Americas Technical Quarterly titled “Beers for the Future.” Alas, it is mostly an examination of the how and why of producing low-alcohol beers. So no nifty predictions about beers made with pumpkins or aged in wine barrels.
However, one table provides a bit of data on the direction American beer was still headed in 1980, the year Sierra Nevada Brewing began selling beer. It compares beers from 10 large brewers in 1957 with 1979 beers in various categories.
Jump forward to 2009. The Barth-Haas Group began analyzing the bitterness levels in brands from around the world in 2006. They measured iso-alpha acids (milligrams per liter), which broadly correspond to International Bitterness Units (IBU). So, with a bit of fudging, 1 mg/L=1 IBU. The 2009 results, published in Brauwelt International in 2011, found that 11 U.S. lagers averaged 7.6 milligrams per liter. The article drew attention to earlier reports that bitterness units were still around 20 in 1980 (see above) and 12 by the late 1990s.
U.S. lagers, South American lagers, and Chinese beers contained the lowest levels of iso-alpha acids (7 to 9 mg/L).