In former times the Brauordnung ("brewing ordinance") decreed, that brewing was allowed only from Michaelmas (29. September) to George (23. April). To bridge the resulting gap, brewers made a special beer, which was longer durable: The Märzen.
Some more hop and stronger boiling of the brew helped to cover the summer times. And we do the same now.
German-Style Märzen
ABV:
5.80%
Giesinger Bräu
Munich, Bavaria, Germany