Franconian style Lager #1 (Kellerbier)

A lager beer brewed like a typical lager beer from Franconia. Also "aU" clone brew.

Friday, October 23, 2020

Upper Franconia is the beer region in Germany. Lots of small breweries, that all mastered the craft of making great lager beer. Often they produce only one lager beer, which range from light to dark-red beers, but most of them are incredible drinkable.

BJCP style 7C tries to reflect this style of beer. Sometimes it's not clear but hazy with varying levels of bitterness and hopiness. One beer, that I like particularly is the "aU" from Mahrs Bräu, Bamberg. It's really good, especially if you can have it at their beer garden. I tried to recreate some properties of this beer in the following recipe.

Recipe

(22l ~69% Efficiency)
1.051 OG - 1.010 FG - 5.0% ABV

2.70kg  (50%) Bohemian Pilsner
2.55kg  (47%) Barke Munich
0.15kg  (03%)  Acidualted

18g (29 IBU) Magnum  60 min
30g (5  IBU) Perle    5 min
20g          Perle    0 min

131ppm Sulfate, 44ppm Chloride (3:1)

Infusion Mash 65°C 60 min, Boil 60 min

L17 Harvest (Augustiner). Pitch at 11°C, 
ramp up to 18°C after 50% attenuation.

I tried to keep the grist as simple as possible. 50/50 Pilsner and Munich, with some Munich malt substituted to reach my desired mash PH. What can I say? Simple turned out to be damn good. As far as I know, Mahrs uses Perle as the only hop for their beer, but I used some Magnum for bittering, because I think it doesn't matter that much for a bittering addition. Towards the end of the boil a generous amount of Perle is added for the desired hop character.
I used the Imperial L17 for this beer, because I like the character a lot, but L13 or W 34/70 will do the job as well I think.
Also I went for a lower carbonation with this beer (~9 psi at ~3°C = 2.3 CO2 volumes = 4.5g/l) because the "aU" stands for "ein Ungespundetes" and ungespundet generally means lower carbonation.

Fermentation

The yeast took ~30 hours to take off as you can see by the temperature drop in the graph, which is normal when I build a starter from a pouch of Imperial Lager yeast. Harvested yeast usually kicks off faster, because I have more cells. After 3 days of active fermentation 50% of the desired attenuation was reached so I raised the temperature to 18 degrees Celsius where it spent another 4 days. 2 days later I cold crashed for 4 days. This was definitely a longer fermentation for me with 13 days from grain to kegging.

Tasting

I really enjoyed this one and still am (now 46 days old), I had a few beer-friends over to taste it and got nothing but good reviews. For my personal taste it was best one week after kegging, when I had said friends over. It was still hazy (see title picture) and had a lot of hop flavour, but well balanced with the clean lager character and the maltiness.

It cleared up now and lost the strong hopiness, but is still a very good, drinkable beer.
It came out quite bitter at ~34 IBU, which I personally liked, but it's a little too bitter to resemble the "aU" closely, so next time I will reduce the bittering hop amount. Also the color could be a little darker to come closer to the goal. I'm not sure yet, if I'll go for Munich II malt or for the addition of some Cara malt next time. The lower carbonation also plays it role to make this beer really good, all the ones I drafted had really fine carbonation. I still don't know if very fine carbonation is a property of lower carbonation in general or the carbonation method.
Overall it compares nicely to the aU. I think the key is a somewhat simple grist and a good chunk of Pilsner malt to keep the FG low and a generous dose of Perle at the end of the boil.

There will definitely be a revision of this beer.