One of the more popular style of beer these days is anything “wild” or “sour”. But these beers are not new, in fact they are some of the oldest styles of beers still in production. Before the days of microbiology and sanitation, and pure culture, likely all beers were “wild” or at least contaminated. I’m not knocking the power of microbial ecology in the stability of beers, but I’m sure most of these were not pure. Aside from the accidents, there is a brewing tradition surrounding “wild beers”…primarily from Belgium but notable wild or sour styles can be from other countries as well, such as Germany. Napoleon Bonaparte is often quoted as saying that berlinerweiss is “the champagne of the north” when he occupied Germany in the early 19th century.
Sourness in beer comes from bacteria (not yeasts) that along with yeasts ferment the sugars in the wort into fermentation products. Since S. cerevisiae is a homo-ethanol fermenter (makes only ethanol and carbon dioxide as products), other organisms are required to produce organic acids that give beer (and other foods and beverages) a sourness. Organic acids one might find in a fermented beverage using some of these bacteria may include lactate, acetate (vinegar), citrate, malate, or succinicate. Typically, Lactobacillus and / or Pediococcus are used in beer production for “sour” ales. Both Lactobacillus and Pediococcus are homo-lactofermenters, which means that the fermentation products formed by those organisms are exclusively lactic acid and carbon dioxide (in the case of Lactobacillus, most Pediococcus species do not produce carbon dioxide as a byproduct). Hetero-lactofermenters, such as the organism used in some sauerkraut production Leuconostoc mesenteroides, produce a mixture of lactic acid and ethanol as fermentation products. It is beyond the scope of this blog to go into the subtlety of why this is but if you are a microbiologist the answer is phosphoketalase.
In a series of posts, I will attempt to describe some of the sour/wild ales that I make. Currently, I have three fermenters going with different blends and strains that I turn over about 2 – 3 times a year. One carboy started out with WLP630, the Berliner Weisse Blend. Each generation (on the fourth now) gets more sour, the Lactobacillus must be increasing with each passage. Another fermentation utilizes dregs beer from a bottle of Cantillon Fou Foune and Cantillon Classic Gueuze, both relatively young. No attempt was made at culture isolation from these beers, just dregs added to wort. The last carboy started out with WLP655 “Belgian Sour Mix 1″…but has since evolved through passage to be a really uniquely funky, tart, lemony sour. I will eventually post all about these batches in subsequent entries.
I treat these carboys as pseudo-solera setups where I never completely drain them but rather drain half of two of them and refill immediately with new wort.
2.5 Gallon Batch
Brew date: July 1st, 2013
Bottling date: March 15, 2014
ABV: 5% (calculated)
70% Pilsen malt
30% Wheat malt
Mash was conducted at 152 F for almost 2 hours, the final temperature was 145 F. Sparge was done with 5 gallons of 170 F water. No pH control was done in the mash and distilled water was used.
I would like to get to a point where I’m doing things like sour / turbid mashes, or following the lenghty and involved brewing schedule real lambic producers use, but this time this was part of a berliner batch that I peeled off to refill the fermenter…so this is actually a no boil beer. I brought the beer up to a boil and just let it chill sitting on the brewstand with the lid on the pot for 8 hours. It got down to about 80 degrees before I poured it back into the fermenters.
No hops were harmed in the production of this beer. These are unhopped ales. I have a bag of aging chinook and amarillo hops that I will eventually begin to incorporate into these brews and I would like to dry hop a few or add other spices, but so far…these are blank slates for the products of fermentation.
This beer was allowed to sit in primary for almost 6 months before being transferred to be bottled. Fermentation took off quickly but leveled off for a while. I would take a sample every month to see the progress. It definitely went through stages, the first stage was an odd looking krausen of white particulate bubbles. These bubbles would pop, they stayed for a few months and then left a broken white surface on the beer. Around month 3, the beer had the texture of mucous (snot). It looked so odd, dangling off the end of the thief I use to draw beer up. It tasted fine, like a lemon / lactic sour but it had the mouthfeel of spit or thicker. I joked that it was the first beer that I made that increased in gravity before decreasing in gravity. Being a microbiologist, I did quickly realize what had happened. Since this beer was being fermented with the dregs from Fou Foune and a classic gueuze, there is no easy way to tell what organisms were pitched into the wort. The thickness of the fermenter is caused by the bacteria Pediococcus (or something related). These bacteria make a class of compounds generally referred to as “exopolysaccharrides”…exo for external (out of the cell), poly for many, and saccharides for sugars. These long chain sugars are usually used to help a bacteria colonize an area or can even inhibit the growth of competing organisms. Not the case here, the thickness cleared up in the end as the Brettanomyces species were able to break down these chains. This is when we arrived at the final product, a thin light colored clear beer with an FG of 1.000.
At the time of bottling, this was only primed to generate the most minimal positive pressure in the bottle. Think of this as an unblended lambic (uncarbonated). I didn’t want to bottle a completely uncarbonated beer since the pressure of the carbon dioxide The fear of acetobacter is pretty high for this one so all packaging was done under carbon dioxide with repetitive sparging of headspace and flushing of the solution with the gas. I believe I was successful in preventing that. This was also an opportunity to finally fire up my beer gun and get that going. Pretty exciting device there, going to get a lot of use out of that now…also I recommend everyone get one…they are pretty great.
Aroma is quite strong and very sour, low on the vinegar, high on lactic acid and citric acid. There is definitely some funk sneaking through, mineral character in the nose.
Beer is light in body, dry on the finish, a mild grainy aftertaste on the finish. The aftertaste gets less and less the more I drink it though. Beer is really bright on the palate, finishing with this sharp citric acid bite. Overall the citric / lemon character wins out in this beer. The overall flavor is strong, very strong. No alcohol present in the flavors and lactic is present in the front of the beer but not the back. I like it…I’ve had much much better beers and I’ve shared several bottles of this with lambic experts, friends of mine, and have gotten a series of comments, some positive, some negative. The most thoughtful comment I received that I agree with is this beer is like a heavily soured Berlinerweiss.
I was hoping for more Brettanomyces character but the sourness wins out, probably Pediococcus more than Lactobacillus. It is a good place to start though and moving forward I think there is room for improvement. I do think that this base could take a fruit flavor quite well too. All things to think about. Overall, I would give this about a 4 out of 5 stars…maybe a little higher than that. It is a good start and has been generally well received.
Possible Improvements for Future Batches:
This project is a lifetime series of tasks for me…seriously. I am committed to figuring this out and these first few serious attempts at sours has been encouraging. I’ve definitely had worse sours from commercial breweries. I first brewed a sour beer about 4 years ago, a simple Berliner…and I haven’t been as committed to controlling the process as I should. First, I would like to actually differentiate the “lambics” (you can criticize my use of the word lambic if you’d like) and the Berlinerweisses in process more. The reality is, this was made with lambic organisms but isn’t a lambic in process, it isn’t cooled via coolship, it was brewed according to lambic tradition, even the malt bill is wrong for a lambic. Subsequent batches of these lambics will be more thoughtful than this. The goal here was to see if I could get a culture from a bottle going, and the strong presence of Pediococcus indicates that these were similar in biology to Cantillon’s own beers and fermentation conditions. I would also like to do some better classic microbiology on the dregs isolated from different lambic brewers…figure out what is actually there. There are a few microbiologists doing this work and I should pay closer attention to them. The isolation and differentiation of the organisms making up the bottle dregs should be pretty easy. Expect future posts from me about organisms isolated from bottles for sure.
Upcoming Sour brews:
This is pretty easy, I’m sitting on more than 7 gallons of various sours that I just have to write up….in addition there is 10 more gallons of sours in fermenters that should be bottled, also looking into fruits for some of these. I think this is an exciting set of beers, for sour lovers or microbiologists. I would like to do some higher resolution microbiology on some of these dregs beer as well, play with different Lactobacillus strains…there are so many things I want to do, the only thing that limits me is time.
“God made yeast, as well as dough, and loves fermentation just as dearly as he loves vegetation.” — Ralph Waldo Emerson