Märzen (or alternatively Maerzen) has its origins in Bavaria, probably before the 16th century. A Bavarian brewing ordinance decreed in 1553 that beer may be brewed only between 29 September and 23 April. The Märzen was brewed in March (März in German is "March") according to a special recipe that would allow the beer to last while the brewing of new beer was forbidden between 24 April and 28 September. The original Märzen was described as "dark brown, full-bodied, and bitter". The beer was often kept in the cellar until late in the summer, and remaining bottles were served at the Oktoberfest.
The style is characterized by a medium to full body, a malty flavour, and a clean dry finish. In Germany, the term covers beers which vary in colour from pale (Helles Märzen), through amber to dark brown (Dunkles Märzen). Common names for Märzen include Märzenbier, Wiener Märzen, Festbier, and Oktoberfestbier.
The Austrian style is light in colour, body, and flavour balance, and is the most popular beer style among the beers in Austria. Austrian Märzenbiers often use caramel malts that impart a sweeter flavour than their German counterparts.
Several American breweries produce their own versions of Oktoberfest-style lager, though few ferment to the same length as traditional Märzen. Interstate-circulated breweries which produce seasonal Oktoberfests include Sam Adams, Great Divide (whose offering is called Hoss), Goose Island, Leinenkugel, Bayern Brewing and Abita. These beers tend to be on the darker amber side of the Oktoberfestbier spectrum.
- "Märzenbier" by Dorst Hornbusch, page 573, "The Oxford Companion to Beer" edited by Garrett Oliver, 2012
- "Oekonomische Encyklopädie" by Johann Georg Krünitz, 1773, vol. 5 page 156.
- "Bierspezialitäten". Märzen. Deutscher Brauer Bund. Retrieved 2006-11-02.
- The New World Guide to Beer, Michael Jackson page 193, ISBN 0-7475-0227-7
- Czech Breweries