The coldest months are peak season for winter beers, a slightly amorphous category defined by production date, alcohol content and spice flavors that can resemble a mincemeat pie. Enjoyed hundreds of years ago in societies such as English and Norse, these tipples fell into a lag only to see a resurgence in the 1970s as winter warmers or Christmas beers. They became a hit in the U.S. after San Francisco's Anchor Brewing released its Christmas ale in 1975, and today include the likes of Sierra Nevada's Celebration IPA, Allagash Brewing's Ski House and Deschutes Brewery's Jubelale.