Technically, authentic Oktoberfest bier is brewed only by the breweries within the city limits of Munich. These are also the only breweries acceptable to participate in the annual Munich Oktoberfest. All other beers brewed to emulate the original must be labeled Oktoberfest-style beer. In spite of their given name, Oktoberfest beers are not brewed in the fall.
They are actually an consequence of the traditional, strong spring brews, called March beers or Marzen, that were put aside in ice-filled caves or cellars for summer consumption. The left-over Marzen was usually finished off in Okotober, when the fresh beers made with the grain and hops from the new harvest season needed to be put into casks. Oktoberfest biers, therefore, are always well-aged, sometimes for three to four months. They are usually deep amber in color and have an alcohol content of 5 to 6.2%.
The first Oktoberfest was not really a festival at all, but the public celebration of the wedding of Crown Prince Luitpold I and Princess. Theressa of Bavaria on October 17, 1810. Held on a large meadow in Munich, the party featured a horse race, beer, food, music and dancing. Anniversary celebrations continued each year, frequently starting in late September and ending in the first week of October. Oktoberfests have been held in Munich for approximately 200 years (with the exception of wartime). As immigrants from Germany came to North America, smaller Oktoberfests sprouted up in their communities.