29 May Beers Gone Wild: Ways To Bring The Sour and The Funk
by Mark E. Lasbury for Indiana On Tap
There are way more than a hundred styles of beer and a million different ways to riff on each of those styles, but the greatest ingenuity in craft beer doesn’t come from thinking of a new ingredient for the mash tun or a way to help finish the beer. Despite the common assumption that the innovation in beer comes from what you put in the wort, it’s the yeast that make beer – brewers’ basically make wort. The magic happens in the fermenter. The many ways to ferment a beer are what give rise to most sours and funky beers, and that means that a given grain bill can produce an almost limitless array of individual beers.
Since our first piece in this series (here) was about the differences between sours and funky beers, this one is going to start talking about the ways to create those beers. The organisms used to make beers tart or funky are many and include both bacteria and yeasts. The number of techniques being used to make these beers is increasing all the time. In fact, several of the hot new techniques have actually been resurrected from older times.
How do you get sour and funk? The ways to make beers sour or funky really all depends on who you hire to turn your wort into beer. Not all funky beers are sour, and not all sour beers are funky. Microbes from different phyla or even kingdoms can be used for fermentation, and will give the beer different characteristics. Yeast are eukaryotic fungi, while bacteria are prokaryotic – the two are as related to each other as humans are to poison ivy. Even within a group of highly related organisms, their properties can produce very different compounds from wort, and that was before humans got their hands on them and starting selectively breeding or otherwise genetically manipulating them.
Remember that for all the organisms we’ll talk about this time and next, when you add them matters. Some could be added at primary fermentation and some at secondary fermentation, some at bottle conditioning, some in a barrel. The combinations of organisms, timing, temperature, and wort characteristics mean that there are literally billions of different beers that can be made. Don’t ever tell me that you’re bored with beer.
Yeasts: Every yeast strain that is commercially available or that may inadvertently fall into a vat of wort from the air to begin fermentation will have a specific temperature range where they will do specific things. At lower temperatures, the fermentation will be a little different than at higher temperatures, in terms of the alcohols produced, the time required to ferment, and the additional products that will be catabolized, metabolized, or anabolized to produce different flavors. Entire companies are dedicated to finding, breeding, storing, propagating, and selling yeast for beer. Other people like to find their own yeast, or store and propagate samples they get from other people – yes, people collect yeasts. Here are a few that produce tart, sour, or funky beers.
1) Saison yeast are Saccharomyces ale-type yeasts (S. cerevisiae) and come in many varieties. Also called farmhouse yeasts and styles of beer, saisons and their yeasts came from the Wallonia region of Belgium where the French speakers predominated. Each farmhouse would have their own recipe and probably their own yeast strain, and the beers were made in the early spring to last through the spring and summer. Saison (translates from French as “season”) were then beers for the working people made with the ingredients that were available in that season.
No single group of beer styles may be driven by the yeast as much as the saisons are. Saison yeasts are efficient, so the beers turn out dry (little residual fermentable sugar), and they carry earthy, funky, and spicy tones. They can be tart, and some saison yeasts will add more acid than others, but saisons don’t need to be sour – the funk is hallmark.
I like saisons that bring a lot of herbal and straw-like flavors with them, while other people like fruitier (more estery) saisons. You can get each from the same malt and hop bills, you just use a different saison yeast strain – and there are a hundred or more of these. Simply said, the yeast makes the saison. Some brewers will add additional flavoring agents, but we like those that let the yeast do the talking.
2) Belgian yeasts are also S. cerevisiae ale yeasts. They are great bringers of flavors that can together be considered funky. In truth, saison yeasts are one type of Belgian yeast, but they have taken on a life of their own and were separated for this discussion. Belgian yeasts strains also number in the hundreds and they can be used to make pales, IPAs, wits, strong ales – both golden and dark….just about any style can be modified by fermenting it with funk and fruit producing Belgian yeasts.
Typical Belgian yeasts produce little acid, so most people wouldn’t consider traditional Belgian styles as tart or sour, but they always earthy, grassy, fruity and/or otherwise funky. Higher alcohols, esters, and phenols make these beers a bit drier (not as dry as typical saisons) and full of spice and fruit – even bubble gum flavors.
Belgian yeast strains date back as far as the 12th century, although trappist and abbey strains are more recent, just a half century old or less. The different strains of yeast are typical for different types of beers, there are strong strains, wit strains, and the abbey and trappist strains produce those special blondes, dubbels, tripels, and quads. Therefore, you could use a trappist strain for a Belgian pale and it would taste great, but it wouldn’t be a belgian pale. You want some great belgians? Indiana is rife with them, Taxman Brewing in Bargersville, Hydraulic Ale Works in Elkhart, Brugge Brasserie in Indianapolis, Blind Owl’s VII Kings and VII Sons in Indy as well.
3) Norwegian farmhouse kveik (pronounced ka-wike, a Norwegian dialect word for “yeast”) can add a bit of tartness and funk, but typically less than other farmhouse yeasts. This is a very interesting yeast and is growing in popularity. We’ll talk more about it soon, but as your homework on this style get to Backstep Brewing in Crawfordsville and try out the kveik beers that Josh Miller is crafting.
4) Brettanomyces yeasts are different from Saccharomyces (biologically different from both S. cerevisiae ale yeast and S. pastorianus lager yeast). There are many strains of brett yeast, and almost all are very efficient fermenters and will ferment more types of sugars, giving drier beers. Because of their high attentuative abilities, bretts are often used for finishing beers and for bottle conditioning. The major strains used in beer are Brettanomyces bruxellensis (called B. brux), Brettanomyces lambicus, and Brettanomyces claussenii.
All three will give some tart acidity, but each will do different things for flavor and aroma profiles. Brett. brux is known to provide of horse blanket characteristic, with a musty and grassy tinge. Brett. lambicus is used in…..lambics of course, but also add depth of flavor to many other styles of beer, including Flanders and oud bruins. Finally, B. claussenii gives more fruit aromas and flavors like pineapple and perhaps cherry, and a bit more acid. It might be the mildest version of the bretts.
Bacteria: Bacteria and beer are frenemies. In most situations bacteria in beer are spoilage agents, the reason a beer is dumped down the drain (or recategorized and renamed). Most bacterial contamination (not really infection – infection refers to invasion of human tissues by microbes or the introduction of DNA into bacteria via a virus) can be avoided through meticulous techniques and thorough cleaning; remember, brewing is mostly cleaning. However, in some cases bacteria can add complexity and new characteristics to beer – especially sour beers; many bacterial species are prolific acid producers.
1) Lactobacilli strains were discussed in decent detail last time for their use in doing kettle sours (here). But they can also be used with other organisms in primary or secondary fermentation. In these situations, Lactobacillus strains add acid bite but little else to the beers. In some cases they can also add some flavors that you might not want, although with the short time they are on the beer, these will be background off flavors. This being said, great beers can be made with kettle souring; for example, the Barn Phantom Series from Triton Brewing in Lawrence are kettle sour beers. The use of fruits and good technique make these beers complex and flavorful, as well as sour.
2) Pediococcus strains are used to make lambics, but they can also be used for other sour/funky beers. “Pedio” strains tend to add acid (mostly lactic, but some others too), but also variable levels of proteins and diacetyl that can add additional flavors. As such, pedio strains are considered cousins to Lactobacillus.
Each pedio strain does something a bit different for the beer, including strains that produce an exopolysaccharide (EPS) that will stick together and cause ropiness. Ropy or “sick” beers are more viscous and at high levels can actually form strands. Given time, other organisms or even pedio will break down the EPS, leaving an even more acidic and flavorful beer with a bigger mouthfeel. Therefore, pedio beers are usually 1) aged much longer, or 2) fermented with brett as well as pedio to break down EPS much faster.
3) Acetobacter strains are used commonly for Flanders Reds and other Flanders style beers (Grand Crus and similar). In fact, acetobacter in any beer other than a Flanders could be considered a contaminant and would be against style. These bacteria produce acetic acid from ethanol as well as some flavoring compounds, but the main addition they provide to a beer is the vinegar aspect.
The fact that they eat up the alcohol might be another reason they are considered contaminants. Interestingly, they need a good amount of oxygen to work, and high levels of dissolved oxygen are usually avoided in making beer. Luckily, since acetobacter is a contaminant in most beer and is undesired, keeping the dissolved oxygen in the wort is a good way to combat contamination. For lambics, the acetobacter is added during aging, so a shake up to add oxygen is required. For lambic primary fermentation, a yeast is needed (often wild), as well as lactobacillus and acetobacter – we’ll talk about this mixed culture fermentation next time.
The baby cousin to the lambic is the meerts beer (Flemish for March). Made with the second runnings of the lambic mash, meerts are lower in alcohol and lighter than lambics. As with lambics, the yeast selection will normally be something wild (see our next article), and they likely have a decent amount of acetobacter-produced vinegar acid, sort of an introduction to the lambic styles. Together, meerts and lambic might be mixed together to produce one of the older;younger blended lambics.
Conclusion. Plenty of sour and/or funky beers can be made under relatively well controlled conditions, using organisms that are well defined. They can be used in solo form or in combination, with timing and levels helping to modify the final product into what the brewer envisioned. But this is only one arm of producing sour/funky beers.
Next time we can talk about the wild part of sour and funky beers. This has less to do with which organisms are being used for fermentation to give sour or wild beers, and more with where those organisms come from and if you happen to know what your fermenting with.
banner image credit: Urban List