Oktoberfestbiers are the beers that have been served at the event in Munich since 1818, and are supplied by 6 breweries known as the Big Six: Spaten, Löwenbräu, Augustiner, Hofbräu, Paulaner and Hacker-Pschorr. Traditionally Oktoberfestbiers were the lagers of around 5.5 to 6% abv called Märzen - brewed in March and allowed to ferment slowly during the summer months. Originally these would have been dark lagers, but from 1872 a strong March brewed version of an amber-red Vienna lager made by Josef Sedlmayr became the favourite Oktoberfestbier.