This week I present a design case study for developing a Marzen beer recipe. Along the way I describe my thought processes as I work through creating and brewing a new recipe.
Designing a Marzen Beer
Before I start a new beer, I sit down and describe what I’m trying to accomplish. This beer was inspired by a trip to Germany I made a few years back. In this case I’m shooting for a well defined beer style – Marzen is category 6A in the 2021 BJCP style guide. It is described as “An amber, malty German lager with a clean, rich, toasty, bready malt flavor, restrained bitterness, and a well-attenuated finish.” It is different from the slightly lighter Oktoberfest style which is better described as a Festbier. I’m hoping to create something that is authentic to the Marzen style. The critical specs are: Color: 8-17 SRM, ABV: 5.6-6.3%, OG: 1.054-1.060 and IBUs: 18-24.
The Malt Bill for Marzen
As is my habit, I start first with the malt bill. All Marzens have a heavy emphasis on Munich malt and this base malt is really the backbone of the style. Traditional Marzens are made with a mix of just Munich and Pilsner malt, so it makes sense to stick with that approach. To get the character out of the malt, I’m going to use a 50% Munich malt base, and the balance of the malt bill will be German Pilsner malt. The specific malt is also important so I purchased actual German Pilsner and Munich malt as the base.
I’m reluctant to add any other malts to a great base, but in this case I did add a small amount of Melanoidin (4%) malt to get a bit more of the decoction character. The idea is that the Melanoidin malt provided a bit of soft maltiness, (not toasty) to give it a bit more character. This is a technique I’ve tried before with good results, though in a podcast discussion with Gordon Strong last year, he recommended against using Melanoidin. So even though I used it I’m not 100% convinced it was needed in this case.
I picked an Original Gravity for the beer of 1.057 which is in the middle of the range for this style. The color with this mix (50% Munich, 46% Pilsner and 4% Melanoidin) came in at 8.9 SRM which is a little on the light side, but should still be a nice amber shade.
Hops Selection and Hop Schedule
Since Marzen highlights the malt and not the hops, the hop decisions for the style are pretty simple. As a traditional German lager, the obvious choice is to use a noble hop. Of the noble hops, something like Saaz would be too spicy. Tettnanger or Hallertauer would be a reasonable choice, and I decided to go with Hallertauer as it is mild and aromatic.
I used a single hop addition with a 60 minute boil as these hops are meant to simply balance out some of the maltiness without being hop forward. I sed the IBU level at 21 IBUs, which again is the middle of the range for the style and should be enough to properly balance the malt bill.
Water Profile
Lagers don’t require a lot of water ion content in general, except to get up into the “good” range for brewing. I started with my local well profile which is pretty close to distilled, except for a moderate (124 ppm) level of bicarbonates. I matched the standard “Lager” profile in Beersmith as close as I could which only added a bit of Calcium and Sulfate in the form of a small Gypsum and Calcium Chloride addition. The resulting profile was good except for the slightly elevated level of bicarbonates from my base water.
Yeast Selection
For yeast I went with the Octoberfest/Marzen Lager strain WLP820 from White Labs. There are certainly other options including their Octoberfest blend WLP833, Munich Lager WLP838 and regular German Lager WLP833, not to mention offerings from other yeast labs. Given that I don’t brew a huge number of lagers, I decided the simple approach would be to use the yeast tied to the style.
The only downside for the WLP820 strain is that it can start slow, so I used a built a generously sized starter to get the yeast going before pitching. Keep in mind you need roughly double the number of yeast cells at pitching for a lager, so a starter is almost always required. On the positive side, this yeast does promote residual sweetness which aids in accenting the overall malty finish.
Mash Schedule
The mash schedule for a German lager are very important to creating the clean malty finish in the beer. For the mash schedule, one might be tempted to use a higher temperature mash conversion step to drive more body and maltiness into the beer. For this style, it would be a mistake, however. The malty flavor is driven by the Munich in the malt bill and low hop rates and not a high finishing gravity.
So instead I decided to use a lager style mash conversion with two steps at both the low and high end of the range as mentioned briefly here and also in this podcast with Gordon Strong. The idea is to use not one but two different conversion steps – one step at the low 140’s (60-62C) and a second step in the mid to high 150’s (69 C). This promotes enzyme activity resulting in a lower overall finishing gravity, but it also aids in enhancing the clean malty finish we associate with German lagers.
For mash pH adjustment, I prefer to drive clean flavored lagers down to the low end of the range – near 5.2. This aids in clarity and I believe helps balance delicately flavored beers. So in this case I added about 2/3 of the lactic acid up front based on my water calculations in BeerSmith and then did a measurement after mashing in and made a final acid adjustment to get down to my target 5.2 range.
Fermentation
The fermentation schedule for a lager is very important. For primary fermentation, I used the recommended temperature of 54 F (12.2 C) for the yeast strain. I let the primary fermentation run for 15 days, and then did a diacetyl rest by raising the temperature a few degrees for 1 day. Next I did a slow ramp down to near freezing over a period of a week for maturation. While not as quick as a cold crash, the slow ramp allows the yeast to clean up many off flavors quickly.
I prefer to mature my lagers for an extended period, so I aged the beer approximately 40 days before kegging, carbonating, and sampling.
Results and Final Recipe
You can view the final recipe here. Overall I was very happy with the result. The finish was clean with a malty finish. It was easy to drink and well balanced. The yeast I picked was a bit slow to start but cleaned the beer up well.
For future versions I would like to try one without the Melanoidin malt after the Gordon Strong interview mentioned above as he believes German lagers are better without it. I also might try another yeast strain, perhaps the German Lager WLP833 or the Munich Lager WLP838 to see if it might start a bit quicker.
I hope you enjoyed this case study. Thanks for joining me on the BeerSmith home brewing blog! Please check out my newsletter and podcast for more great brewing tips!
