#44 Traditional Berliner Weisse

Eureka, the following brew is one of the weirdest I have done so far. The recipe I am talking about is a Berliner Weisse recipe influenced by a traditional way to get it sour.

The story begins in Berlin, 1908. A man named Otto Francke patented a method to get a more consistent sourness in Berliner Weisse beers. The old way to sour a Berliner Weisse was to get the sourness from lactic acid producing bacteria during the fermentation. One disadvantages of this method was the inconsistent sourness. Otto Francke’s method changed that. Those of you who are familiar with German find the patent here. A short summary of his process: The process basically is about sour mashing. Otto Francke describes a method were you add lactic acid forming bacteria to your mash and let it ferment until the sourness is at an appropriate level. I assume that a kind of Lactobacillus strain was used for this task. Then you just heat up the whole mash and kill the bacteria. The level of sourness is now fixed. Then cool it down and let it ferment with a yeast.

The following information are from a thesis I got from a homebrewer in Germany. The thesis’ title in English is “About the flavor formation in Berliner wheat beer regarding acids and esters” and was written by F.J. Methner in 1987.

As already mentioned, there are at least two different strategies to sour a Berliner Weisse. The first one involves a pre-souring of the mash with the addition of Lactobacillus as described above. The wort is then pasteurized and fermented with a Saccharomyces strain and Brettanomyces bruxellensis is added at bottling. Yes, there were some Brettanomyces in the beer as well. This method is useful to get a consistent sourness. Another method to sour the beer is pitching Lactobacillus in addition to yeast for the fermentation. The important step here is to pitch a least a 1:1 ratio of the Lactobacillus: yeast cells. If there are more yeast cells than Lactobacillus at the beginning, the growth of the yeast can prevent the Lactobacillus and therefore lead to a lower sourness. Some of you familiar with Lactobacillus might know that some Lactobacillus strains are hop sensitive. One example of such a strain is the one available from Wyeast, Lactobacillus delbrueckii. This strain can therefore be used for sour mashing because there are no hops in the mash at this time. Problems could arise when you use this strain in the fermentation vessel for souring as there were hops in the wort or mash. Hop-insensitive strains such as L. brevis can be used for souring during the fermentation. But this strain is not available for homebrewers as far as I know.

Another interesting fact about sourness, the sourness in unboiled worts get higher than in boiled worts. The boiling seems to hinder the Lactobacillus in some way. It is therefore advisable to use a no-boil technique if the souring will be done in the fermenter.

The history and techniques of Berliner Weisse breweries in Berlin are not very well documented and research is still going on. This research and documentation seem very important to me since the Berliner Weisse breweries are very limited in Germany and the knowledge of Berliner Weisse brewing might get lost. Luckily there is a growing homebrewer community which helps to keep the knowledge of Berliner Weisse brewing. But there are some homebrewers in Germany as well who try to replicate the old Berliner Weisse that once existed. Luckily for me, all the old articles about Berliner Weisse are written in German and therefore have no problem understanding them.

So I planned on doing a sour mash as well but did not add any kind of Lactobacillus, just some additional malt. There should be some kind of Lactobacillus on the grains to get the mash to the appropriate sourness level. Lets first get through the recipe, details about the process are mentioned below. I used J. Zainasheff’s “Saures Biergesicht” recipe and tweaked it a bit.

Recipe: Traditionelle Berliner Weisse
Numbers: Volume [L] 18 (4.8 gal)
Original gravity 10.4°P
Terminal gravity Not yet measured
Color Around 6 EBC
Grains: Pilsner Malt (4 EBC) 1.9 kg
Wheat Malt (4 EBC) 1.36 kg
Acidified malt (6 EBC) 0.2 kg (added after pre-mashing)
Hops: Hallertauer (4% AA) 28 g Mash hops
Yeast: #1338 European Ale
Water: Burgdorf Mash: 8.5 L (2.2 gal), sparge: 23 L (6.1 gal) @78°C (172°F)
Rest: Pre-mash Mash in @66°C (151°F), 60 min @ 66°C (151°F), cool down to 50°C (131°F) and add 0.2 kg of acidified malt. Leave mash for two days at around 38°C (100°F).
Second mash Add hops and heat up to 78°C. Rest 15 min @ 78°C (172°F).
Boil: No boil
Fermentation: Primary 7 days @ 20°C (68°F) in a plastic bucket
Secondary N/A
Maturation: Carbonation (CO2 vol) 3.5 vol for bottles, 1.75 vol for keg
Maturation time 3-4 months

02/10/12: Brew day. Crushed the malts and mashed them in at 65°C. Then held the mash at this temperature for an hour. I then let the mash cool down to approximately 50°C (131°F) and added some crushed acidified malt. I then set my electrical kettle to 38°C (100°F) and let it sit.

Fig 1: Souring mash after 24 h at 38°C (100°F)

Luckily, there is no smell coming with the pictures. The smell after 24 h was just incredible (Fig 1). There were some notes of fermented lemons, some sourness, and a very overpowering smell of vomit… The heat helped to distribute the smell evenly in my basement. And the mash was bubbling a bit (see white bubbles at the surface in Fig 1). Well, the smell was just too much! I was very close to dumb the whole thing to get rid of the smell in the basement. But I left the mash sour for another 24 h. By the way, there was some sourness detectable as I tasted the mash.

Fig 2: Added the hops to the mash

Then happened the first miracle. The next morning, the mash now rested for nearly 48 h, the vomit smell was gone, although still in my basement, but there was a very pleasant lemony smell. And the mash was even more sour than the day before. So I proceeded with my mission to replicate an original Berliner Weisse. I then added the hops directly into the mash and heated the whole thing up to 78°C (172°F) and left it there for 15 minutes. Then sparged the wort directly into the fermenter.

Fig 3: Mash is resting at 78°C

Another interesting thing here was the consistency of the mash. The mash was a kind of mushy as it can be seen in Fig 3. And this made the sparging a really hard job. I tried three different false bottoms I have for fly sparging. I then decided to go with a batch sparge. This did not improved the whole sparging a bit. So I went for a stir-and-flow technique. I first stirred up the whole mash and collected the runnings until it got stuck and repeated this process until the fermenter was full. I guess I do not have to mention that my efficiency of this batch was one of the lowest ever….

I then let the fermenter cool down outside and pitched a package of Wyeast’s European Ale yeast. Another thing that made me worry was the European Ale yeast. I know that this particular strain tends to a very long lag-phase before proceeding to the fermentation. But the fermenter stayed there for nearly two days without any signs of fermentation, kräusen or change in gravity. I already assumed that maybe the souring could have altered the mash in a way to make it unfermentable for the yeast. But then, another miracle, the fermentation took off after two days.

02/28/12: Bottling time. I added some table sugar for the appropriate carbonation levels and bottled half of the batch in a 9 L keg (2.4 gal) and the remaining liters into bottles. I then added some sediment from my BFM dregs, which include a Brettanomyces strain, to each bottle. No Bretts for the keg. The bottles and keg will now mature for nearly three to four months. I am really looking forward how this brew turns out. I hope that the tasting will be the third miracle…

By the way, I had a look at the mash with my microscope. And I could see a lot of different bacteria in there… Stay tuned for the tasting in late June.

07/19/2012: Uploaded the tasting notes of the share with Brettanomyces.


12 thoughts on “#44 Traditional Berliner Weisse

  1. Cool! Looking forward to your tasting notes. I’ll be posting mine, both fermented plain and with raspberry, sometime in the next few months as well. I also went with the no boil approach.
    It’s great that you mention the use of Brettanomyces because here in the States there is quite a bit of argument about it. Some say some Brett is OK in Berliner, others say that it absolutely should not be present and only use of Lactobacillus and Saccharomyces is allowed, while others say that Berliner should be fermented with Brett and whatever else lives on grain. I fermented mine with 3 Brett strains in addition to Saccharomyces and other microbes hahaha so there!

  2. I am looking forward to your tasting notes as well. I am aware of the discussions you mentioned. In my opinion, there are at least two different things to remember:

    – If you want a traditional Berliner Weisse, there must be some Bretts bruxellensis in there. This is a conclusion in the stated thesis above in the post. If no Bretts are in there, the flavor profile of the wheat beer will not be like a traditional one. This fact is in some way verified since traditional wheat beers are very similar to Belgian Gueuze concerning the spectrum of aroma (also mentioned in the thesis). So far for the traditional wheat beer.

    – For other wheat beers, produced with Saccharomyces and Lactobacillus, the aroma is similar to the general beers. So no Bretts.

    Well, if you plan on doing a traditional Berliner Weisse, then there could be the sour-mashing (with addition of a Lactobacillus strain), hops in the mash and the no boil method. Then just Saccharomyces and Brettanomyces. I can’t tell where exactly the Brettanomyces are introduced. Some results point to the use as a bottling yeast. I am not sure if the breweries back then added Brettanomyces deliberately. Or if the Bretts were in wooden barrels? You could even sour the beer during the fermentation with a Lacto strain (not L. delbrueckii) as well and then introduce Bretts. There could be other methods for sure. I guess you could brew a lambic without Brettanomyces as well, but would it taste like a lambic?!? I guess no. And it would not be a lambic as well then, right? For me, the Bretts absolutely belong into the lambic and for a traditional Berliner Weisse as well.

    The problem the breweries had (and the homebrewers now have…) is the lack of sourness or the inconsistent amount of sourness with the souring done during the fermentation. That’s why some of the breweries seemed to have changed their brewing techniques and switched to the sour mashing. But this has nothing to do with the Bretts.

    To summarize, Bretts belong into a traditional Berliner Weisse. No Bretts in a Berliner Weisse works as well, but you don’t get a traditional Berliner Weisse then. I would call this a neo-Berliner Weisse. I guess your approach would be a way it could have been done back in the days in Berlin.

    Some thought about the method to ferment your Weisse only with Brett and the bugs from the grains. I would say that Bretts were in the beer back then by accident. So no fermentation with Bretts only. And the techniques they used back then would have killed most of the bacteria from the grains and the yeasts for sure. The only way to introduce the bugs from the grains back into the wort would have been to add some grains to the cooled wort. But I see no evidence for that so far.

    But I will do further research on the whole Berliner Weisse topic and maybe post about it?

    • Sure that would be great to learn more about it! I’m planning another 55L batch of Berliner in the next week or two (with some twists, of course, because it’s more fun). Mine wasn’t all Brett and Saccharomyces was by far the main fermentor, but Bretts played their part.

      • Cool, I hope all goes according to plan. And I am really excited how your raspberry infused Berliner turns out. I’ll try to write a short story about Berliner Weisse in the future. But it seems that I already mentioned the most important things already.

        Good luck with your Weisse,

  3. Have you by any chance ever worked with butyric acid in the lab? I know it’s supposed to be a foul-smelling acid found in vomit (so says Wikipedia), so I am curious if that’s what the stink is. I mentioned in another comment somewhere that this same smell (I am assuming) happens a lot when creating a new sourdough starter. I also recall reading some instructions for sour mashing and the author talked about Clostridium species creating a terrible smell. I know some of them are butyric acid producers.

    Actually, last time it happened to me it also smelled a bit of bubblegum. Afterwards I found a description of ethyl butyrate that said it smelled like that.

    Just a theory!

    • I have in fact worked with butyric acid before. And yes, it kind of smells like a concentrated smell of wet socks… Pretty bad! But the smell I had there in the cellar was in my opinion something different. But there could be some butyric acid. Maybe the concentration was too low or high to remind me of the butyric acid.

      I posted about my smelling experience in a homebrewing forum and someone mentioned Clostridium botulinium 🙂 Maybe there are indeed some sort of Clostridium involved in the souring of the mash?

      And there is another homebrewer who experienced a similar smell development: (http://www.homebrewtalk.com/f127/berliner-ish-292502/)

      • Oh, I think I know exactly the smell you are talking about. I’ve also had that one happen on the first day or two of a starter, followed by the vomit smell. Ick. You’re still well so I’m going to guess it’s not C. botulinum 🙂

        I see that somebody on that HBT thread recommended keeping the heat above 110F. The sour mash instructions I was talking about are from BYO, and there he recommends 120F to avoid the stink. So it looks like your temps were just a little too low.


        If you’re curious, here’s some stuff on the subject from a baker/microbiologist:


        She had a lab identify the species at various stages of the process, and comes up with a novel solution of using acidic liquids instead of water to begin the process with the pH down to less inviting territory. That’s something I want to try with wort for “capturing” ambient or grain flora. If I could skip the enteric bacteria I’d be very happy.


        • Thank you for the BYO article and the other links. The toxin botox is not really heat stable, raising the mash after the sour mashing should have denaturated the toxin if it ever would have been in there… 🙂

          As far as I know there are some enteric bacteria involved in the spontaneous fermentation at early stages. But these bacteria get inactivated at lower pH levels. I imagine that lowering the pH for sour mashing or harvesting bugs from grains could inhibit some nasty bugs indeed. But thats just an assumption.


    • Hi there, I will post about the tasting for sure. I can already tell that the version without the Bretts is not very sour. On the other hand, the one with Bretts is quite sour. Although not the level I was hoping for. A tasting is scheduled for Friday and I hope to publish the notes by the end of the next week. Stay tuned!

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