In the simplest definition, Viennas are amber-colored beers brewed with bottom-fermenting lager yeast. On the other hand, the terms Märzen and Oktoberfest originally referred to a brewing process—not a beer style. While the terms Vienna, Märzen and Oktoberfest may seem unrelated, history indicates otherwise. Over time, Viennas became standard beers brewed on a regular basis and often at a l…