Today, most people probably associate Oktoberfest with lighter beer styles that tend towards a light, and often slightly stronger, pilsner. However, the original Oktoberfest style is somewhat darker and stronger, and is now best known as Märzen.
Historically, this was brewed in Bavaria around March in spring (March = Märzen), and had to be brewed somewhat strong to last through the summer, and all the way to Oktoberfest. The reason for this is old laws that prohibited brewing in summer (April 23rd to September 29th), simply because high temperatures during brewing could lead to fire or explosions. In other words, for a period it was illegal to brew in summer due to increased fire risk.
The beer style is a dark, strong lager, which can be seen as a stronger variant of Vienna lager. Think of flavors like bread, biscuits, and caramel, often slightly toasted. Otherwise, this should be a clean fermented lager beer without any big flavors or bitterness from the hops. Here, the malt should take center stage.
Ingredients for brewing Märzen
Malt:
In the malt base, a combination of pilsner and munich malt is often used. In addition, it is common to add a proportion of specialty malt such as biscuit, crystal/caramel malt, or caramunich to bring out flavors of caramel and dried fruit. To achieve a slightly dry finish and more color, a small proportion (a couple of percent of the malt base) of roasted malt such as black, roasted barley, or chocolate is often used. Remember that the malt base should shine in this beer style, so this is where you should fine-tune.
Hops:
Hops should not primarily be the focus in this style, so you can easily use only bittering hops here. Typical high-alpha German noble hops (Magnum) are perfect for this, up to around 25 IBU. If you still want to experiment a bit, other German noble hops can work well for a while during the boil. Think Mittelfruh, Tettnang, Hersbrucker, or even Saaz. Some American hop varieties like Mt Hood have also been used with great success in this style, but don't overdo the hops; less is more.
Yeast:
Classic German bottom-fermenting strains will work fine here. WLP820 would be the first choice here, as it is a yeast culture specifically designed for Märzen. Good alternatives would also be WLP833, which really highlights the malt character, but be aware that it doesn't become too sweet and lean towards bock instead. If we look at dry yeast, M76 Bavarian Lager is a variant that is very similar to WLP820, or alternatively Saflager 34/70 which ferments cleanly and simply. For those who are in a hurry or struggle with temperature control, Oslo Kveik from Bootleg Biology can also be an alternative for this. This yeast type can ferment beer with lager character in just a few days at high temperatures.
Brewing Process
The brewing process itself is no more complicated than usual. The most important part of brewing here is temperature control during fermentation. Since this style should be completely clean, and there are no hops that can hide off-flavors, temperature control is incredibly important here. If the temperature varies significantly during the fermentation process, less pleasant flavors like sulfur (rotten eggs) or diacetyl (butter) can quickly shine through. Keep the temperature low and stable at around 10 degrees Celsius, and increase the temperature a few degrees towards the very end of the fermentation process to clean up any residual diacetyl. Feel free to check out our article on temperature control during fermentation to learn more about the subject.
As history suggests, this is a type of beer that needs some aging time before it reaches its best. Brew it in March, and serve it in October for the truly authentic experience. And of course, it must be served in appropriate glasses, such as sturdy seidel glasses.
Feel free to take a look at our excellent all-grain beer kit, Festival Bräu - Märzen Lager.
