LA Craft Beer Blog - First Post

Hello World!

I’m Adrian, MacLeod’s resident Numbers Guy, and welcome to the first post of MacLeod’s new Blog. I know what you’re thinking - What is this, the 90’s? Is there a market for a brewery-based blog? Should we all go out for Laser Tag and watch Jurassic Park on VHS at Timmy’s step-dad’s place after this? (I was a kid in the 90s, I have no idea what adults were doing. Was laser-disc a 90s thing? I refuse to google “laser-disc.”)

Well, fair question, and I don’t have an answer for you now, but I hope to build one over time in the form of a blog on beer, and brewing, and maybe Bayesian statistics and its use in predicting beer competition winners from past competitions and online beer reviews, that’s worth reading.

So without further ado, let’s talk briefly about Cask Conditioning since we are, after all, a Brit-ish brewery.

CAMRA - a bunch of nerds and their thoughts on Cask Conditioning

In response to declining sales of what CAMRA refers to as “Real Ale” in the UK, a group calling itself CAMRA, or the “Campaign for Real Ale” sprung up in the 70s to bolster support for the waning, if not exactly dying, practice of Cask-Conditioned Ale in pubs.

As part of their mission statement, they’ve outlined a list of requirements for beer to be called “Real Ale,” and we’ll ignore all of those for the purposes of brevity (and hence, wit), save one

In comparison to other types of beer that kill off the yeast and artificially inject the beer with CO2 prior to serving, real ale contains live yeast which continues to condition and ferments the beer until it is served.”

And this is a legitimate point; the vast majority of beer produced in the world is force-carbonated, even if the larger breweries use recaptured CO2 to some extent to do so, and one subtle consequence is that in this process, the beer is exposed to the (admittedly very small quantities of) non-CO2 gases in commercial cylinders of CO2 (you can thank Entropy for the virtual guarantee of contamination). I’m unaware of any of these components being harmful, but oxygen is a regular member of the cast, and as such, you run the risk of at least somewhat shortening your shelf-life and producing off flavors, possibly below taste thresholds granted, when force carbonating.

So, what can we do about this? As CAMRA puts forth, we can absolutely make use of the yeast we already have in suspension to produce chemically pure CO2 (and, of course, byproducts that we don’t mind like ethanol) either in the serving vessel, as is the case with Cask-Conditioned beer, or as the Germans often do, in Fermenters and Brite Tanks using Spunding Valves (devices that vent CO2, say, if the pressure exceeds a set pressure, say, 12 psi).

But the gamut is broad, so I figured it’d be a fun challenge to write out all of the variations I could recall, that are actually used in commercial breweries.

The Rules

The game is simple - we need to seal the serving container or brite tank, with residual or added sugar and yeast, and allow the two to produce carbonation, relying on no external source of CO2 except for potentially pushing beer from vessel to vessel.

The Full Gamut

1) Racking to the Cask while there’s sugar still in solution

I’m not sure how common this is today, but it’s certainly an option, and one mentioned in David Sutula’s excellent Mild Ale, p154.

“There [the beer] is allowed to continue fermenting slowly, either by way of the residual yeast feeding on the remaining sugars or as a result of dosing the beer with yeast or sugar or some combination of the two.”

Spoiler alert!

2) Adding priming sugar to the cask, but no new yeast

Yeast is pretty hardy, so this is very often possible, and the wise and economical choice. The only exception would be if you’ve filtered the bejeezus out of the beer, or it underwent a very difficult fermentation (very low pH, very high OG), or if it’s very old, like a barrel-aged beer, or any combination thereof. 

3) Adding priming sugar to the cask, but yes new yeast

This is then the alternative, but of course carries the risk of contamination. Interestingly, Lallemand actually sells a specific yeast for pitching into what I’d imagine is the brite tank or fermenter pre-casking, which is akin to the homebrew practice of “bulk priming,” but with yeast. Speaking of, we at MacLeod prime each cask, but I have no idea how common this is - the advantage is that you never over- or under-prime your casks since you know your exact volume for each cask, but the downside is labor and variation in carb levels if you’re not super careful with measuring/filling casks/making sure the yeast dose is vaguely similar cask-to-cask (this is probably a non-issue except in the extreme).

4) Kräusening

Since bottled CO2 is obviously a new invention (I’ve always suspected without proof that it was connected to Steam Engine technology for obvious reasons, but I’ve never looked into it), every beer (and sparkling wine) culture has had to rely on yeast for their carbonation. And while force carbonation is by far the default in homebrewing and professional brewing in the US (I’m pretty sure Budweiser, say, doesn’t spund), the Germans have a similarly rich history with carbonation, which can be seen in Kräusening, Spunding valves, Fässers, and Kellerbiers.

I’m extremely likely to talk about these in a later post, but for now let’s talk Kräusening, pronounced (Croix-sun-ing, with Croix pronounced as in La Croix). Also, while we’re at it, it’s “Hof-broy” Haus - German may be a bit tough, but it’s remarkably consistent with its pronunciation scheme.

So kräusening - this the absolutely gangster practice of taking actively fermenting beer, which naturally has some unfermented sugar in it, and pitching that into a finished beer that you’d like to carbonate, and then either sealing that up in a cask or spunding it in a finishing tank, somewhat similar to top-cropping.

Another upside to this technique is that it reportedly produces cleaner beer, as the hungry yeast start working through their sleepy hosts’ unfinished byproducts once they work through the wort sugars. 

And finally, the versatility of this baller technique can be seen in its use not just for carbonation, but as a source of fresh yeast for new wort, like a giant starter. It’s way, way harder to do this on a homebrew level, but if you’re brewing basically the same beer every day, or at least often brew a clean base beer like a Helles or something, this is super straight-forward.

Conclusion

So yeah, that’s the world of cask conditioning in a nutshell. Is it worth it? I mean, probably - if you’re making ridiculously good beer and want an extra .5%, or if you’re very concerned about shelf life/O2, and/or if you have no great way to package beer without O2 pickup, then go for it. I personally never do it, in part because on the classic homebrew 12 oz bottle scale I have terrible luck with hitting my carbonation targets, but spunding is definitely in my future (I’ve done it before and it’s easy as heck, but you’d have to rack to a new vessel post-spunding to really get a clean product, which is why I’m not stoked on it), and on a brewery scale, it’s viable and sensible for subtle, malt-driven beers, if not really for clean lagers or heavily-hopped beers in my experience.

And if you’d like to mess around, start here.

Cheers!

Adrian Febre

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