Hello Sour Beer Friends!
Once I decided to create this blog, one of the ideas that I have been most excited about was the opportunity that it would give me to interact with the sour beer community. Although at this point the site is little more than a month old, I have already gotten some very positive feedback from fellow sour beer fans out there! Personally, I really enjoy getting to share my insight and experiences with my readers, and I love to help educate people in any way that I can. To this end I will be answering any questions that I can on the site in a regularly updated feature called “Ask Dr. Lambic”. I want to encourage anyone who has questions about an article or review that I’ve written, about brewing, or about sour beers in general to please send them in either through the site, or through my Facebook or Twitter feeds. I very much look forward to hearing from you!
With that said, I would like to kick off “Ask Dr. Lambic” by answering a question I received today in response to my review Two Pennsylvania Berliner Weisses:
“I am starting a brewery in Minnesota and looking forward to taking my ten gallon batches of Berliner Weisse into 15 BBL batches. When you say confusion over how to brew the style and DMS issues, can you elaborate on this?” – Richard Drawdy
Thank you Richard for being the first to write in with a question! To give a little background for those of you who may be unfamiliar with the Berliner Weisse style, it is a low alcohol sour wheat ale traditionally brewed in Germany. Berliner Weisses are typically made with a blend of approximately half wheat and half pilsner malt. They have very restrained hopping for low bitterness and no apparent hop flavor or aroma. Traditional examples are very sessionable at approximately 2.8% to 3.8% ABV (although American examples do sometimes push this up to below 5%). These beers will have a sharp souring profile made entirely from lactic acid with no presence of acetic acid (vinegar). Brettanomyces is typically absent from these sours but if it is used in the fermentation its characteristics should be restrained to doughy or tropical fruit notes without any significant presence of leathery, cheesy, or barnyard characteristics. Typically these beers will have a light cracker and dough like malt sweetness with noticeable wheat flavor and a medium to high level of souring. The finish should be dry and refreshing and the body of the beer should be low to medium with a high level of carbonation. Berliner Weisses are typically the “cleanest” of the sour beers. They generally have little to no funk and are a fairly straightforward mixture of tangy yogurt and lemon-like sourness with a wheat flavored malt backbone. Easy drinking and refreshing would be keywords to describe these beers.
When brewing these beers, there are several approaches that I have seen used with success. Some brewers mash and boil these beers as they would with any others, then pitching a mixed culture of Lactobacillus and Saccharomyces at the same time to sour and ferment the beer. In this method the beer will typically need to age for several months to achieve souring. I would caution that if aging a light wheat beer for this length of time, a brewer will need to be very careful to protect the beer from oxygen to avoid staling of the wheat character and to avoid potential acetic acid formation. Additionally this method may result in a beer that is only lightly sour and the beer may need to have additional acid added to the final product to achieve the intended level of souring.
Another popular method of brewing this beer would be the “sour mash” method. In this method a typical mash is carried out at first. Rather than sparging, the mash is cooled down to about 105 to 115 degrees F and a handful of fresh grain is dropped into the mash. This temperature is held for a day or two during which time Lactobacillus and other potential bacteria in the grain bed sour the beer. After this time the mash can be heated up to sparging temperature and a regular sparge and boil can be carried out. This method is popular because the boil will kill off any souring bacteria before the beer goes into the fermenters. This method typically works well to achieve a higher level of souring in the beer although due to the less predictable environment and potential microbes in the grain bed this method can yield unpredictable results. Occasionally this method can lead to stinkier and more enteric characteristics (aromas of manure and flavors of bile). However, if some care is taken to protect the sour mash from oxygen these funky off-flavors and aromas can generally be avoided.
A third method used to sour these beers would be a “sour kettle” or “sour wort” method. In the sour kettle method the grain is mashed and sparged as usual, and then a standard boil takes place. After the boil the wort is cooled to 105-115 F and held in the kettle. Here the handful of un-crushed base malt or culture of Lactobacillus is added and the wort sours over several days while being held at this warm temperature. After souring, the beer is returned to a boil, chilled and fermented with Saccharomyces. This method attempts to remove some of the unpredictability of the sour mash by killing off all the stray microbes from the mash before adding a hopefully more pure dose of Lactobacillus. This method also then kills off the Lactobacillus after souring so that no souring bacteria go into the fermenters. Of course this method has the drawback of tying up your boil kettle for several days. The “sour wort” method is practically identical except that the wort is kept warm in the fermenter with only Lactobacillus souring the wort for several days before the yeast is pitched. In the sour wort method the Lactobacillus is never killed off it is only given first-shot at the high sugar wort for several days before Saccharomyces is added.
Each of these methods can produce excellent results when dialed in for a brewers system and processes. Both the mixed culture and the sour wort methods will produce beers with living Lactobacillus in the final product so the beer’s flavor and sourness may evolve over time while the sour mash and sour kettle methods both will produce beers with a fixed level of acidity.
One process I have not mentioned yet but has become popular (especially in homebrewing circles) is the no-boil approach. In this method the mash is conducted as usual and the beer is then sparged directly into a fermenter, completely bypassing the boil. The idea here is that by bypassing the boil, some Lactobacillus (which lives naturally on the surface of all base malt) will survive the mash and can go to work souring the beer directly. This method is sometimes combined with sour mashing or sour kettling to increase the population of Lactobacillus and produce more souring more quickly.
So now to discuss what I meant by “confusion over how to brew the style”. The problem with a lot of Berliner Weisses that I have tasted is that they often taste like they contain the water drained out a can of cooked corn which indicates that there is a lot of DMS (DiMethyl Sulfide) present in these beers. All barley malt naturally contains a flavorless chemical called SMM (S-Methyl Methionine). When heated, SMM is converted to DMS (which has the flavor of cooked corn). Luckily DMS is very volitile and readily boils off from a beer during a normal rolling boil. SMM levels are especially high in very lightly kilned malts like pilsner malt, making these malts especially prone to the production of DMS and necessitating longer boil times (generally 90-120 minutes).
Here’s the issue: Most Berliner Weisse recipes call for about 50% pilsner malt which is very prone to the formation of DMS and DMS can form at temperatures well below boiling such as those held during a typical sparge (168 degrees F). Therefore, even under the best circumstances the no-boil method can lead to some level of DMS in the beer. The really big problem occurs when brewers try to combine the no boil method with the sour mash method. Because these brewers want to kill off the Lactobacillus before the wort reaches the fermenter, they will often bring the wort up to a short boil (for like 15 minutes) to pasteurize the beer. This short boil, in essence, is producing a ton of DMS without giving the wort a long enough boil to get rid of it.
All of these various brewing techniques can and have produced great Berliner Weisses when care is taken to perform them properly. In my experiences, the two major off flavors I have tasted in various examples of Berliner Weiss are either the presence of DMS or the presence of fecal aromas or bile-like flavors arising from a sour mash that went too wild. In the case of the sour mash, if it works for you go for it, but if the beer is coming out fecal, astringent, solventy, like bile, like sweat, strongly musty, or dirty tasting, opt for the sour kettle or sour wort methods of souring. If you want to try no-boil, you have to fully commit to it… don’t boil the beer at all and when mashing and sparging try to keep your temperatures a little on the cool side. Otherwise, mash as normal and use any souring method you prefer but give your wort a full 90 minute rolling boil to eliminate DMS problems.
Thank you again Richard for your question! If any readers would like to see their questions answered on the site or have recommendations for articles or reviews please send them in.
Great article, Dr.L ! I am currently finding my Berliner Weiss is funky with DMS and as your article stated it must have been from the 15 min boil after the sour kettling. Currently I have my batch crash cooling and I found (from your advise) that I needed a pinch of winemakers acid blend and that seemed to round out the sour flavors. I am looking forward to revisiting this beer again after scouring this article hahha!
Well I couldn’t imagine a more well spelled out all encompassing answer and I am so grateful for that! Now to elaborate a bit on the method I have been using is the sour mash method, and I have tried kettle souring as well. Mash is 50/50 pils/wheat and add 10% the mash weight uncrushed pils to 120f wort or mash and let rest for about 48 hours usually. I have gotten mostly consistent and delicious results with this method. Clean, lemon, intense tangy tartness. Easy drinker. One batch did end up having a crazy amount of sulfur which I attributed to a too cold American ale fermentation which faded after a few weeks in the package. If you were to suggest the most foolproof way to produce the ideal Berliner as you describe what would it be? I am contemplating sour mash or sour kettle with grain for the lacto. My mash tun has no steam but the kettle does so I am leaning towards kettle souring.
Thank you for the compliment! I personally lean towards scientific repeatability when it comes to making sour beers. One of my goals as a brewer is to remove some of the mystery behind using various strains and species of bacteria and Brettanomyces to help brewers achieve more predictable results with their sour beers. On a commercial scale I think I would use a full wort boil combined with either the sour kettle or sour wort method depending upon whether you want lacto entering your fermenters.
Also, since various grain lots may contain different strains of lactobacillus, I would use grain as a source until I produced a batch with superior flavor characteristics and then I would maintain a starter culture of the lacto from that batch to use in subsequent batches.
Best of luck! I look forward to trying your beers someday.
I was looking for information regarding DMS and Berliner Weisse, I was thinking about doing a 15 min boil. Looks like I’ll give it the 90 min boil treatment.
How can I keep my wort at 100 degrees for several days in the boil kettle? Just periodically heat it up?
That is the way it is done on a professional scale. For homebrewers it’s often easier to transfer into a keg or carboy, insulate it, and use an electric heating device like a ferm-wrap to keep it warm.
Thanks Matt! Hey, I caught your segment on the Sour Hour! Love that podcast and thats cool your supporting it! Sounds like you have some awesome beer. Anyway.. funny you mention fermenting in a carboy because thats exactly what I was thinking about this morning while driving in to work. I heard on that podcast that its very important to keep oxygen out and that you can purge with CO2. So I was thinking, well what if I just move it in to a carboy after mashing, add the Lacto and then close it up and hit it with a little CO2. I wouldnt normally think this is a good idea with the primary fermentation because there is no airlock, but what about for this method? Anything in particular you think I need to do or worry about with this method? Thanks for the help! I had a Anderson Valley Gose recently and I really want to try and make something like that for summer.
Thanks Chad! You can definitely use carboys for a Lacto fermentation. I’ve done it frequently. I would recommend chilling the wort down to around 110F or cooler and make sure to heat the carboy up with hot water to avoid shattering glass from heat shock. Even safer go with a better bottle. Also, if using a carboy its a good idea to use an airlock. It won’t hurt the Lacto fermentation and you never want to seal up glass. Alternatively you can use a foam stopper covered in aluminum foil. Any oxygen ingress will be minimal and shouldn’t cause problems. Make sure to check out our article on brewing a Gose and good luck with yours!
Ok so I just started the boil after doing a lacto starter that was at around 105 for 3 days and then pitched into a carboy of wort. Same temp Sun-Thurs and the first day I came home from work the airlock was empty. It had a crack and all the water was gone. Replaced it but now that I’m smelling the wort at the boil, it has very similar smell as spent grain that has been left in the mash tun for a day or two. Sour and a little unpleasant. Is this expected and will go away after boil and fermentation or is that the type of thing I’m trying to avoid? pH seems to be around 3.8 as best I can tell by the strips.
I’m just checking that I understand your methods. Did you boil the wort before adding the Lacto starter to it and then reboil after 3 days?
No, I did a mash, racked it to the carboy and then pitched the lacto starter.
The problem with sour mashing is that it’s hard to prevent stray bacteria from making off flavors and aromas in the wort. In the future, boil for at least 15 minutes before you run into the carboy to kill off unwanted bacteria. Also pH adjusting before pitching Lacto is another safeguard. Check out my article on Fast Souring with Lactobacillus for a review of these steps. Your best bet at this point is to run your Sacc fermentation and then taste the results to see what you’ve got.
It’s beginning to smell a little more like normal as the boil goes on. The smell prior to boiling almost left like a vomit smell in the air. Quite unpleasant..
I’m planning on doing a no boil, double decoction mash for a Berliner this weekend. The plan is to boil the second decoction for 20 minutes before adding it back to the main mash for a 152F rest. Do you think that would be a recipe for DMS? Thanks for supporting The Sour Hour too.
It’s really hard to say, I’ve had no boil Berliners that are dripping with DMS and others that haven’t had any. I think that if you are going for a no boil method. It’s very important to run a vigorous and healthy fermentation to drive off any potential DMS. Otherwise I would opt for a full boil after running the mash regime you are planning. Either option should work well. Thanks for reading the site and I’m very proud to be a sponsor of the show. Cheers!
I wanted to share my experience with that last batch I tried in the previous post. The foul smell went down some after the boil and primary fermentation but it was just too much to drink. The taste was not quite as strong and was somewhat drinkable but the nose was just too off putting. I just recently tried Destihl’s Wild Sour Gose and I thought that beer had a very similar smell. So now I’m mashing my second try at this. I did a lacto starter and I just smelled it. It’s not strong but that smell is definitely present. I’m starting to wonder if that’s just a by product of lacto. Thoughts? I’ve had a few Gose beers and Berliners that are clean and have no smells like that present at all. Thanks for your input!
Vomit-like smells are a very common off-aroma when doing sour mash or sour kettle processes but they aren’t a feature of Lactobacillus in isolation. What strain are you using to create your starter or are you using grain?
I’m kind of thinking it’s just the smell of heated yeast. I’m probably just paranoid now and have a somewhat untrained nose for the smells. I’m sure its a normal smell. I used Wyeast 5335. I have it in the carboy now. Boiled the mash for about 15 mins prior to pitching so I think this round should be better.
Do you have any favorite sacch strains for fermenting a sour mashed berliner? Any that have a good tolerance of low pH? I’d be interested to see how a saison strain would pair with a sour mashed berliner… any experience?
I’ve enjoyed several Berliners that have simply used the California Ale (Chico) strain. That being said I don’t actually brew a lot of Berliner Weisse. My personal brewing tends towards the longer aged and blended sours. I can say that saison strains tend to do well with lower pH fermentation but their spicy characteristics may be a bit out of style for a Berliner.
If i wanted to stop the souring (lacto) process, basically want to kill any bugs, what length of boil would be sufficient? i assume just hitting a boil would probably do it, but should i be safe and boil for 15, 30?
also this pasteurizing period would give me a chance to add some hop character (albeit low, less than 10 ibu for the style) without hindering the lacto production in previous steps. is that when you add hops or do you tend to add them at first boil and keep them low enough not to kill the lacto?
Generally 15 minutes of boiling is quoted as the minimum timeframe for sanitizing wort. Personally I always opt for longer boils with the goal of better wort clarification and reduction of potential DMS, but I am comfortable with 15 minutes from a sanitation perspective. Also if you are souring and then boiling, the boiling process will not eliminate any lactic acid already created, it will just kill Lactobacillus and any other organisms that could potentially sour the beer further down the pipeline.
The sour beer bug has bitten me. It started with sourdough bread!!!! So I’ve been “souring” my beer using my sourdough starter. The question I have here is that you are souring before the boil which is pretty clever and I’m thinking that this would be my next way forward. I don’t have kettle to spare for the whole time so looking at using something like a better bottle. I’m using BIAB so till now I’ve just been separating the spent grain before the boil. Does the souring require the grain with the liquor or should I separate the grains before souring?
I would recommend separating the grains, performing a short boil, cool, add your sourdough starter, let the beer sour, then reboil for longer. Check out my Fast Souring With Lactobacillus article for more details. Lactobacillus is the souring organism in sourdough starters.
Thanks for the reply and that fill’s in the missing step in my head. I’ll give it a try this evening. Just refreshed the sourdough starter this morning so should be good to go by this evening.
Hello great sight. I am currently making a no-boil and its been fermenting for 3 weeks. I took a sample and it tastes very watery. However the sourness is developing. Should I move it to a secondary or just leave it for a few more weeks? The recipe did not specify and called for a 6 week fermentation.
What microbes were pitched into this beer? I’m assuming the gravity started in the 1.030’s? Some more details about your recipe and process would help me make recommendations.
here is the link to the recipe. I followed it exactly. It is beginning to get more sour. It just doesn’t have much flavor. Tastes like a slightly sour water. I moved it to a secondary fermentation on September 17th It was brewed on August 13th. The white labs WLP677 was used. I took the OG reading when it was transferred to secondary and it was 1.005. I didn’t take the original OG I forgot to take it. Its probably going to be less than 2%. Can I possibly add something while its in secondary to kick it up?
Ok so I got a refractometer reading for my Berliner the SG is 1.015 but that’s after fermenting for 6 weeks. I don’t know if that will help. Tasted it again it is still developing the sour taste but not much beer flavor.
Hi Dr. Lambic, thanks for putting so much time and effort into this site, I love it. I brewed my first Berliner Weisse recently and would like to know your thoughts on some questions I have.
I mashed 50/50 pilsner and wheat malt, sparged, boiled the wort for 15 minutes, and then cooled to 104F and put my kettle in my insulated box and pitched Wyeast 5335 – I did not make a starter, just pitched from the smack-pack (which I had warmed up etc. beforehand). The wort temperature drifted down from 104F to 86F over the next 36 hours. Then I boiled it for 60 minutes with 5 IBUs of Tettnanger. Post-boil gravity was 1.032, exactly on target. I cooled it to 70F, transferred to a sealed bucket, let the trub fall out for about 8 hours, then split my 5 gallons between two plastic car-boys. Then I pitched a re-hydrated sachet of US-04 (because that’s all I had on hand) between the two. (I’m going to put some fruit in one and leave the other “as is”).
Regarding pH, I only have strips so the readings are not very accurate, but after the 36 hours in the box the pH had gone down to “about” 4.5 to 5 – I guess I should have tried harder to maintain the temperature at a steady 100F or so, and maybe left it for longer, but that’s okay by me because it’s only my first attempt etc. and I don’t want it to be particularly sour anyway. There was a very thin krausen skin on top of the wort.
Now, about 5 days later, one of the car-boys has dropped to 1.022, while the other is at 1.028. The krausen is nothing like what I would normally see: instead, it’s a bunch of thin bubbles covering 3/4 of the surface of the beer. It tastes fine and is a lovely light colour, with no obvious off-flavours or aromas, but it’s not exactly a raging fermentation at this point.
I was wondering:
– should I pitch some more Sacc to get the fermentation going stronger? I’m worried that it’s struggling.
– I’m thinking now that a pH meter is pretty much essential equipment for sour brewing – would you agree?
– do you have any comments or advice on what I’ve done here? I’d love a few tips!
Thanks again and cheers, Mark
Thank you for the compliments on the site! It’s always exciting to hear when someone is brewing their first sour beer. I do agree with your assessment that a pH meter is vital to brewing these styles. It’s difficult to say even now what the pH of this beer may be and how that could be affecting the fermentation. My instinct based on the strain chosen and the pitch rate would be that the pH is not sour enough to be hampering the fermentation of US-04. The fermentation may be a bit sluggish due to low oxygen levels in the wort after the souring process, but it’s difficult to say whether that is the case. Especially given the fact that a rehydrated packet of US-04 should contain more than enough cells to fully ferment the wort. Of course, the low krausen could also just be a result of lower foam stability / head retention common in Lactobacillus-first beers. I doubt that it’s necessary to pitch more Sacc at this point, especially if the flavor seems good. I would let the batches stay the course and see how they turn out. If for some reason they stall completely above 1.015 or so, then I would pitch in some fresh yeast and raise the fermentation temperature a bit to encourage them to fully attenuate. Good luck and keep brewing sour!
Thanks Matt – since I wrote, the fermentation has kicked in a bit more; there’s regular air-lock activity so I’ll take your advice and let it roll. I’ve ordered a pH meter!
Hi Matt – just for info (and to show off a little), the Berliner Weisse I brewed scored a 45 at the local homebrew comp and took 2nd place overall. It’s a really good beer, thanks for your help, tips, and advice!
That’s great to hear Mark! Congrats! I’m glad that I could be of help. Cheers!
Hi Dr. Lambic,
Quick question on the first method described. I plan to follow this method and pitch my lacto and sacc strains together after transferring to a carboy (boil or not boil I have not decided on yet). My question pertains to what temperature am I cooling the wort before pitching? I would assume that I would cool to sacc temp ranges 65F-68F? I just want make sure I am not getting this method and sour wort method mixed up.
If co-pitching both Lacto and Sacc, you will want to use the recommended temperature for your strain of Sacc. I would recommend using a Lacto strain that is known to perform well at lower temperatures such as Omega Yeast’s Lacto Blend, or L. plantarum from Goodbelly or pro-biotic sources.
I also read over at http://www.milkthefunk.com/wiki/Dimethyl_Sulfide, low pH increases the SMM half-life, so probably need to bump up from the standard 90 minute for pilsner.
Hi Dr Lambic. First of all thank you very much for sharing your knowledge!
After reading a lot from your blog and others, I decided to brew my first berliner weisse.
70% weyermann (NOT floor malted) pils, 30% wheat to OG 1032- FG 1010. I do BIAB and “half batches” (10L).
I did a multi step mash with low mineral/balanced-to-malty sulphate/cl ratio and mash-ph5.3 water, boiled with 1/2tablet of deltafloc for 15′, then chilled to 35ºC (95ºF) lowered the ph with 88% lactic acid to around 4.5 and added the content of 5 Lactobacillus L. Plantarum capsules each one containing 20Billion cells (Ethical Nutrients Inner Health IBS support from a drugstore in Sydney) = 10Billion/L.
I kept the kettle into my fermenter fridge (with a mini heater) with the temp controller set to 35ºC (95ºF).
After around 26h I did a second 15′ boil with halletau for 5IBU and yeast nutrient (I always boil without the lid).
Pitched 2pkts of Safale US-05 at 18ºC (64.4ºF) and raised 0.5ºC every 12 hours until 21ºC (70ºF).
After having the same gravity reading for 3 days (diacetyl rest) y bottled and carbonated to 3.2vol.
1 week later I opened a bottle and it was crisp, light, refreshing, well carbonated, good foam, amazing head retention, a little hazy but not turbid and the sourness was perfect to my taste, very noticeable but not overwhelming.
All good… but… after the souring, before the second mini-boil, I felt quite an odd flavour/aroma, I can’t describe it other way than “acid-honey”, like that aftertaste when you have this kind of very dense and viscous un-processed rosemary honey. My girlfriend says she loves it, but I’m not sure if that’s normal. I’ve studied all the off-flavours and I can’t identify it. Is not buttery or corn or medicinal or stinky or cheese… it smells good and tastes good, like a lemonade with honey, but I’m not sure if it’s wrong, and if it is I don’t have a clue of what I did wrong.
I should try a regular berliner weisse, but I can only find them with fruit :S
What do you think? Any clue?
Just to clarify: The aroma you are describing is not present in the bottled beer, it was only present after the fermentation of Lactobacillus before the second boil?
If that is the case it is quite normal for Lactobacillus to create a variety of aromas that range from vegetal and sauerkraut-like to floral depending upon the strains used. Many of the less desirable aromas of Lactobacillus can be removed through a second boil or reduced during active fermentation by yeast.
Cheers to your first Berliner Weisse!