Brewers have been experimenting with pumpkin since colonial times, but the pumpkin beers we know today didn’t appear until the early 1980s. As the story goes, California-based photographer and brewer Bill Owens adapted a recipe attributed to George Washington, and added pumpkin pie spice to the second batch after finding the first lacked distinct flavor. Since then, brewers nationwide have released their own pumpkin beers each fall, usually flavored with spices that mimic pumpkin pie flavor...