“Märzen” is German for March.

Centuries ago in Bavaria, brewing during the hot summer months was risky because warmer temperatures made beer more likely to spoil. Brewers would produce one final batch in March, brewing it slightly stronger and hopping it a little more to help it keep through the summer while it matured in cool cellars and caves.

When autumn arrived, those perfectly conditioned beers were ready to be enjoyed during the harvest season, and eventually became the traditional beer served at Munich’s Oktoberfest.