There where some requests on Milk the Funk to create a recipe for a historic Berliner Weisse.
So I did my best to create an historical accurate Version with some minor adjustments to bring it in the modern world.
7.3 Plato (1029 SG)
70% Wheat Malt
30% Pilsner Malt
2-7 IBU Hallertau Mittelfrüh
German Ale / Kölsch (WLP029, Wyeast 1007)
Berliner Weisse Brettanomyces (Escarpment Labs)
Lactobacillus Brevis (WLP672, OYL-605 etc.)
63°C for 60 minutes
72°C for 20 minutes
78°C mash out
For water target roughly 100 ppm Calcium, 50 ppm of Chloride and 100 ppm of Sulfite. Just before mash out draw a thin decoction and boil the hops in it for 15 minutes, add it to the mash while raising the temperature to mash out. After lautering do not boil the wort, just heat the wort to 98°C to pasteurize then cool. Pre-acidify the wort to a pH of 4.5 for foam stability. Ferment at room temperature (18-20°C) for roughly 3 months. Carbonate to 7-9 g/l CO2 (3.5-4.5 volumes), use heavy bottles.
This is my idea of the recipe, I will go through every point and the background behind my decision. Let’s start with the grain bill. Historically Berliner Weisse was brewed with different ratios of wheat and barley, sometimes as low as 1:2 sometimes as high as 4:1. For me the sweet spot is at 70% wheat and 30% barley, there is enough mouthfeel and doughiness from the wheat and the lautering is for most homebrew systems manageable. Another point you should consider is using a wheat with a high level of protein, and if possible undermodified. The reason for this decision is the improvement of the foam stability, which is one of the quality signs of a good Berliner Weisse. If you don’t have access to such a malt, you can add 35% torrefied or chitted wheat. The water profile is the current one from Berlin, you could also try using a 2:1 chloride:sulfite ratio for a thicker mouthfeel.
For mashing I opted for a „Hochkurz“ mashing scheme (60 minutes at 63°C and 20 minutes at 72°C) which favours fermentability. The reason for that is that I believe that more simple, available sugars lead to a less funky/sour wort. My theory is that in a highly fermentable wort Saccharomyces leaves less fermentables to Brettanomyces and Lactic acid bacteria (LAB) and flavour wise Brettanomyces is focuses more on esterase. Another factor is that the beer is finished faster. You can also use a infusion mash at 65°C which a lot of brewers used in the old days.
When starting with a culture I would suggest going as low as 2 IBU with the hopping, later when the culture is rolling you can go up to 7 maybe even 10 IBUs in order to balance the acidity. If you are using Pediococcus (more on that later when we talk about bacteria) you can use a bit more than 10 IBUs since it is more hop tollerant. Also you can use a small amount (2 g/l) of dry hopping with Hallertau Mittelfrüh after fermentation in order to improve head retention.
In the last 5 years a lot of people isolated Berliner Weisse Brettanomyces strains out of old bottles and even some where kept alive. Thanks to people like Richard Preiss from Escarpment labs we can now use those historic strains and brew with them. In my experience those strains when handled right develop nearly no funky, phenolic aroma. In my opinion the main function for Brettanomyces in Berliner Weisse is its capability to transform lactic and acetic acid to ethyl lactate and ethyl acetate. In order to avoid stressing the Brettanomyces I suggest making a good starter to ensure a high cell count in the mixed culture. When you grow up the mixed culture just let it sit for a few weeks to achieve balance. If you don’t have access to a original Berliner Weisse Strain you could use a Brettanomyces anomala strain like OYL-201 or WLP645. For Saccharomyces I would recommend a clean slightly fruity strain like WLP029 (German Ale/Kölsch).
The main Lactobacillus that was found in Berliner Weisse was Lactobacillus Brevis. Also there where other hop tolerant strains present like L. lindnerii, L. casei, L. coryniformis and L. plantarum but L. Brevis was mostly present. Another aspect of old time Berliner production was the presence of Pediococcus. Sometimes the beers went ropy, when that happened the brewer needed to sit on the beer for a few months in order to get rid of the ropiness. After that it was priced for it’s delicate flavour. I have Pediococcus present in my culture, it will get ropey after 3 weeks and goes away at month 2-3. With Pediococcus in your culture the beer will get more sour than without.
In my opinion not boiling the wort adds some perceivable differences to the finished product. First the color is pretty pale and second there is a grainy doughy flavour that comes through. It is necessary to boil the hops in a decoction for not boiling the wort. Another topic is fermentation time. In the old days they would ferment and know when to bottle in order to achieve the right carbonation level (this is called „Grünschlauchen“ in german). I would advise against that until you really know your culture and can predict when it will stop. Targeting a high carbonation level is also a key to the style, why else would Napoleon call it „champagne of the north“. When bottling and priming be sure to use the method to account for terminal acid shock. My observations was that adding fresh yeast at bottling time suppresses/delays the development of the typical Brett funk a bit.
When you where following most of the steps you should end up with a straw coloured beer that has an aroma reminiscent of peaches and apricots. It has a thick rocky white head which persists (the hardest thing to achieve). The mouthfeel is creamy due to the high carbonation, but dries out after you swallow. There is a grainy, dough like aftertaste. It is tart and balanced but not overly sour or puckering. The refreshing qualities of a good Berliner Weisse will leave you longing for the 1 litre goblets they where using in the beginning of the 20th century.