On Brewing Experiments, a Dissenting View

Last week, I commented enthusiastically on Breakside's recent offering of five versions of a porter, each with one different adjunct. Vasilios Gletsos, MacTarnahan's brewer, added a comment I'd like to share.

I'm probably getting lost here at the end of the comments section, with all the excitement and all, but I wanted to suggest that this kind of thing happens at commercial breweries all the time, as part of the R&D process. It is just that the decision is typically made by the brewer before releasing the beer about which one is best.

Also, what is 'best' can also have different criteria. Like for yeast: how does it perform in the cellar?, flocculation, attenuation, longevity, and of course flavor profile, among many other questions.

We often trial different hops in our standard brews or quantites of spices, etc. What is unique here is that Ben is presenting the beers and letting the public decide for themselves. I would personally feel uncomfortable putting out a beer if I thought some other example worked better.

I have no doubt that Vasili speaks for lots and lots of commercial breweries here. A brewery is in the business of offering the very best product it can; beta versions may work for software, but not beer. Fair enough. I wouldn't expect to see a brewery's work as it's hammering out a new recipe (although Deschutes regularly releases in-development recipes to beer at their brewpubs).

What Breakside did is a little different. Ben used a recipe that was already excellent--it didn't occur to me to ask, but I assume he was pleased with it. With that recipe, he made four variants that used a single different ingredient. That's the kind of thing I'd like to see. Take MacTarnahan's for example. It's a beer made exclusively with Cascade hops. It would be absolutely fascinating to see the brewery do a few other versions that used different hops--everything else being identical (process, IBUs, etc.). It'll be a cold day in hell before they do it, but I'd love it. (Or, if you prefer, Mac's with different English and American ale strains.)

There's no right answer. One thing I've learned in talking with scores of brewers over the years is that they all have definite ideas about what they're doing--and these ideas are in no way identical. So I'll put Vasili in the "no" column. Any other takers?

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.

Bittering Units - Measuring Hoppiness

So in my reviews, I used stats that included the enigmatic "BUs" (sometimes rendered "IBUs") . This stands for bittering units (or international bittering units), and it's a standard chemical equation for how much alpha acid from hops is utilized in a beer. It's fairly useful shorthand for estimating how bitter a beer is going to be, with a few caveats. I'll try to use them as often as possible when writing about beers, so this handy primer should be valuable.

What Hops Do
Without hops, beer would varying degrees of sweet (depending on the amount and fermentation of the malt), something like a breakfast cereal. Hops, which have a complex chemical structure, are used principally for bittering--they offset the sickly sweet of malt and make a beer drinkable. The chemical in the hop that creates bitterness is known as "alpha acid." Hops have a multitude of other chemicals, though (some of which are not well understood), and these contribute other flavors and aroma. Each hop has its own character, so those aromas and flavors vary. So, two beers hopped at the same alpha level but with different hops will be roughly as "bitter," but will taste different.

Caveats

1. Bitterness is a perceived, not absolute, quality. There are some hops I find intensely bitter like English Target. To my tongue, they produce a far more bitter beer than one made from an equivalent amount of alpha acids derived from, say, Chinook.
2. Bitterness Units are only a mathematical calculation of the percent of alpha acids per ounce. The more malt used in a beer, the less bitter it will be. So if a pale ale has 35 BUs, it will taste pretty hoppy, but an imperial stout with only 35 BUs would be overly sweet.
3. Much of the flavor that comes from hops isn't bitter. BridgePort IPA has 50 BUs, but few people would describe it as "bitter" because the hop concoction (there are five varieties) is so citrusy.
   

Using BUs
An average beer is around 5% alcohol by volume (1.050 OG). Roughly speaking, this is how bitterness would be perceived in that beer based on BUs:

BUs
10-15 - almost no perceived bitterness (industrial lagers)
14-20 - mild (golden ales, wheat beers)
20-30 - some bitterness (brown ales, English bitter)
30-40 - pronounced bitterness (pilsners, pale ales, porters)
40-50 - sharp bitterness (IPAs)
50+ saturated, intense bitterness

Some beers are super hopped, in part because of high malt bills. A few examples:

Strong ales - 40-65 BUs
Imperial stouts - 50-80 BUs
Barleywines - 60-100 BUs
Imperial or double IPAs - 65-100 BUs