For 16 days leading up to the first Sunday in October there is a festival celebrated in Munich, Germany called die Wiesn. More popularly known, and celebrated, as Oktoberfest, the festival has been celebrated for just over 200 years. The festival takes place at Theresienwiese (The Fields of Therese) which is named after Princess Therese of Saxe-Hildburghausen, and is held yearly to commemorate her marriage to the Crown Prince Ludwig I in the year 1810.
Oktoberfest to most brings to mind beer, which in this case is traditionally known as a Märzen. Brewed in March (März) or the springtime, a Märzen was stored through the summer when it was too warm for brewing, it was kept in a cool place to be ready for the fall. Typically a Märzen is a red or copper colored beer with a toasty warm flavor which is perfect for the Autumn in every way.
While there are many beers that can be found that are called Oktoberfest, only a few are found in the celebration in Munich. One criteria is that the beer must be brewed within the city limits. It must also conform to the Reinheitsgebot, or German Beer Purity Law. The Reinheitsgebot, dates back to the year 1516 and states that only water, barley and hops could be used in the production of beer.
As a homebrewer, the first thing that comes to my mind is where is the yeast? After all, yeast is required to convert the sugars in the malts to alcohol which is the process of fermentation required to make beer. In fact yeast can be found and can begin fermenting naturally. Vats of wort (pre-fermented beer) could be left to the open air until fermentation begins or residue from former brewing could also begin the process by either being found in the brewery or by being added to the beer, much like sourdough is passed on; by taking a little from the old and adding to the new.
Beers which can be found at the festival in Munich are :Augustiner-Bräu, Hacker-Pschorr-Bräu, Löwenbräu, Paulaner-BräuSpatenbräu and Staatliches Hofbräu-München. Several of these can be found imported in your local grocery or beer store.