When Brettanomcyes Sneak In

For the most part, American breweries are now happy to tango with brettanomyces--at least on their own terms.  There are a few who have no interest in wild yeasts, and Full Sail is one--at least, I don't recall any forays they may have made into the funk. Or anyway, intentional forays.  I discovered last night that they have made at least one unintentionally.

Earlier this year, I went out to the brewery to see the latest year-old Top Sail Imperial Porter come out of the barrels.  As you know, every year, Full Sail puts a strong dark ale in barrels and lets them sit there a year; then they blend the barrels together and release them as Top Sail or Black Gold Imperial Stout.  When I visited, they were tasting beer as it came out of the barrel, flagging any batches that had gone south.  Barrels are not precise instruments, and in a certain percentage of them, something goes wrong.  Anything that tasted a bit funky got this treatment:

But here's the thing.  Brettanomyces work very slowly.  I've been in three different barrel rooms where a brewer has discovered a cask that a resident colony, heretofore unbeknownst to the brewery, has begun souring the beer inside.  It takes months for them to reproduce enough that they make their presence known.  it's easy to miss them until they've affected the beer sufficiently.  Their elusiveness is compounded in a process like Full Sail's, where all the barrels are blended together before bottling. 

After my visit, Jamie Emmerson gave me a couple bottles of vintage beers from Full Sail's own cellar.  One of the bottles was an '09 Black Gold, which I cracked last night.  It's no secret where I'm headed.  In 2009, one of those barrels had a bit of the wild culture going on--and after three years, it finally expressed itself. The bottle I had was still fairly mild--just a bit tart and vinous--but it was unmistakable.  Indeed, the flavor was probably not far from the historic London porters of the 19th century.  It had a certain refined quality to it that I quite enjoyed.  Full Sail probably won't be excited to hear it, but that's what happens when you use old whisky barrels--sometimes they harbor wild things.

If anyone else has '09s laying around, I'd be interested to hear what they taste like.
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PHOTO: DOCTOR ROSE

Ahead of His Time

How early did the idea of pitching brettanomyces occur to someone? Almost instantly:

The holder of the patent is N. Hjelte Claussen, the scientist who discovered brettanomyces at Carlsberg. I'm going to go ahead and hazard the observation that the Wiki site on his strain--brettanomyces claussenii--is wrong; it says he discovered the strain in 1904. Nice trick securing a patent on this technique a year before he discovered the actual strain.

I'll hazard a second observation as well: Claussen's scheme to pitch brett into lagers doesn't seem to have taken off. Sour lager (sauerlagern?)? Someone should give that a shot--there's a gold medal at the GABF waiting for the first brewery to perfect it.

It didn't really pan out for English beers, either, though you could credit Claussen with amazing foresight. It only took commercial breweries a century to start pitching brett after he suggested it. Wonder if that patent's still good?


Update: In comments Ron Pattinson writes:

It didn't take 100 years for someone to pitch brettanomyces. Courage were doing it with Russian Stout in the 1970's and probably started a good bit before that.

I've also an East German Porter recipe from the 1950's that says to add brettanomyces for secondary conditioning.

What Sours a Beer?

In yesterday's post about Devil's Kriek, Samurai Artist sparked a conversation about the souring properties of brettanomyces. Since sour beers are becoming more common, it's a timely discussion. Sourness may be tart and clean as in a Berliner Weisse, dry and austere as in some lambics, our face-puckeringly intense, as in some Flemish reds. These different qualities come from different microorganisms, and it's worth spending a post mentioning a few of the biggies.

My source material here is Jeff Sparrow's Wild Brews, which I recommend highly for anyone interested in a deep understanding of sour beers. Let's start with a pithy opening from the start of his fourth chapter, "Beer-Souring Microorganisms." Here, he describes the actors that create the funk:

"Four dominant types of microorganisms commonly ferment and acidify wild beers: brettanomyces, lactobacillus, pediococcus, and saccharomyces. Sever other important players also merit a mention, including acetobacter, enterobacter, and various oxidative yeasts."

Now, in this next pithy passage, he describes the particular nature of the funk those actors produce:

"The acids most important to wild beers include lactic and acetic acid. Acetic acid, present in copious amounts in vinegar, is sharp, pungent, and greatly increases the perception of sourness. Lactic acid, found in spoiled milk, is less objectionable and contributes a 'tangy' character, sometime perceived as 'sweet' by brewers in contrast to other acids."

(There are actually a host of other acids that contribute flavor like caproic acid, which Sparrow says gives a "goaty," "sweaty," or "zoolike" character. But you can read his book if you want the full monty.)

Brettanomyces
This wild yeast inspires the most awe and fear among brewers. It will eat anything, including dextrins and sugars that other yeasts find unpalatable, achieving nearly 100% attenuation. (Brewers joke that it will start eating the glass in a bottle if you leave it long enough.) Attenuation is the percentage of available sugars a yeast will eat. Wyeast's Northwest ale yeast, a non-brettanomyces yeast, attenuates at about 70%, for example. Brett will produce both acetic and lactic acids, but the former only under certain circumstances. There are at least five species of brettanomyces and many strains within each. The most common is brettanomyces bruxellensis, named for a strain from Brussels.

Lactobacillus
Lactobacillus is a type of wild yeast bacteria that gives Flanders beers (red and brown) their character, as it does to some German ales like Gose and Berliner Weisse. It is not a major player in lambics, however--the lactic there comes from pediococcus (see below). As the name suggests, lactobacillus produces lactic acid. Lactobacillus is far more finicky than brettanomyces, preferring warm temperatures, a low-oxygen environment, and low levels of hop acids.

Pediococcus
As alluded to above, pediococcus is the beastie that gives lambics their lactic, not lactobacillus. This is mainly a function of the life cycle of a lambic. Pediococcus ferments in beer with little or no oxygen; likewise, it gives off no carbon dioxide. In a lambic, the pediococcus kicks in after 3-4 months when, fascinatingly, the wort is exceptionally sour as a result of early enterobacter production. The pediococcus begins when the lambic warms up, creating "long strands of slime" on top of the wort. You can drink the beer at this stage, but it's oily and known as the "sick" stage. But from the sickness comes the lactic, and eventually, the slime is reabsorbed as the brettanomyces begin gobbling up everything that's left.

The upshot? "Sour" isn't a fixed flavor. Different beers have different compounds and acids that contribute characteristics that define style. Brewers have very different attitudes to the kinds of sour beers produce. When I was at Allagash last year, Jason Perkins and Rob Tod described their efforts to cultivate native brettanomyces. On the other hand, Ron Gansberg doesn't want brett in his brewery; he's a lactobacillus man. Matt Swihart is a brett man, but is he only a brett man, or will future batches exhibit the character of other funky bacteria? I guess we'll have to wait and see.



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PHOTO: Cantillon casks, Thom's Beer Blog / link

Update.
By the way, Sparrow reproduces a lot of very cool graphs he got from Raj Apte, and you can find those at his site. One I particularly enjoyed is a graph showing the waves of activity in lambic fermentation, particularly in the first year. Click on it to see an enlarged version. You'll find more cool stuff if you follow the link to his site, too.

To Brett or Not to Brett

A few weeks ago, when I visited the Rac Lodge, I asked Ron if he used any brettanomyces in his beer. The look he gave me was akin to the expression a tower guardsman might wear while observing a horde of Huns swarming over the moat. Emphatically no.

I don't blame him. When you're messing around with wild yeasts, the decision about whether to invite Brett over is one not to take lightly. Brett is the Kali of yeasts, the destroyer of cities, eater of young. To add it to your beer is to submit to forces beyond your control, to cede dominion to a single-celled organism.

I was reminded of this decision as Sally and I watched the Oscars on Sunday. (Not a bad show, and I was psyched to see Sean Penn win for best actor in what I thought was the year's best film. Gus should have taken the statue for directing, and Slumdog was vastly over-rated. Still, seeing the glee of the half-Indian crew made up for the misplaced lauding.) We pulled out an '08 Cascade Kriek and a Dissident. In the former, no brettanomyces; in the latter, ample stores of the lush, horse-blankety bad boy.

There's a remarkable difference in the way the two have aged. The Kriek is much as I remember it from a year ago. The cherry character has faded a bit and become less distinct, but that's to be expected. The intensity of sour remains about where it was, as does the level of sweetness. In short, the yeast have pooped out, and any changes to the beer now are unrelated to their activity.

The Dissident, though--what a change! Here's what I wrote in my review in September:

[T]there's none of that skanky brett, but rather a sweet chocolate and sour cherry-accented nose. As it opened up, the astringency of the sour diminished a little and the cherries muscled their way in.

It is a lovely and approachable beer.... The body is creamy and rich, with malt notes contributing a brown sugar/biscuit base. Onto this are balanced the twin flavors of tart/sweet cherries and the sourness of the yeast and cultures.

It's a totally different beer now. The brett have muscled their way in; the beer has their characteristic horsey aroma, and the palate their musty sourness. And they've continued to break the beer down--it is now bone dry. The malt notes are gone, and the body, while still rich, is less creamy and more vinous. Anyone who fell in love with this beer in the fall might now find it too intense and lacking in that velvety luxury they admired. But for those who revel in the character of brett, this is something else. The progression is very similar to Orval's--the young and older versions of the beer don't even appear to be related, much less the same being. At the time of release, Deschutes listed Dissident as 8.8% alcohol. Based on the way Orval gets stronger, I'd bet it's well into double digits now.

Whether 'tis nobler in the glass to suffer
the stings and dryness of outrageous chemistry...
To brett or not to brett, that is the question.