Kaboom!

[mr.jay]

So I get to work yesterday, and discover a 20 foot radius of spattered beer in the brewery. It was on the walls, on the equipment, on some tables in the dining room, everywhere. The culprit at the center of this circle of destruction, a cask, minus one shive? (or bung, not sure which one sits at the top). It blew off with such force, the piece was wedged in the drywall on the ceiling above!! (and these are some high ceilings). Thank the Lord nobody was there when it happened. I had 3 casks in there, all filled to equal amounts, all filled at the same time. What could cause such a powerful explosion in only one of the casks? The other casks are fine. I actually chilled them down, and tapped one today, expecting to get sprayed. No problems, in fact, the beer is just right.

Obviously, I know very little about casks (I would certainly like to know more) Is there an exhaustive source of information for a guy such as myself? I have been serving casks for about 6 months now, and manage to produce a decent product in the end, but my "real ale" confidence level is not where it should be. Put it this way, I am comfortable enough to cask condition a beer on occasion, but not comfortable enough to teach somebody else how to do it properly. This needs to change.

[wailingguitar]

2 good possibilities; Did you prime all the beer together or each individually in their own cask? If each cask was primed individually, there is a chance that the one that leaked was accidentally over primed. Too much fermentable=too much gas=kaboom. Of course there is the chance that the cask in question had something unpleasant living in it... infections frequently cause excess gas and then kaboom.

[tamper]

"Cellermanship" is a great book on cask ale. I bought my copy through Amazon UK.

[tariq khan]

cask kaboom

I've had keystones and shives blow out but it mainly happens during the warmer months....Casks do not like warm temperatures....That would be the first thing I'd look at. Also use wooden shives, which rarely pop out in my experience or the plastic long tail ones which are a bitch to de-shive when cleaning casks but do the job to keep the beer in......


T

[BlenderCrab]

an idea

I had a few casks overpressurize (two of three blew the keystones out) a few months ago -- and I'm pretty sure I isolated the problem(s).

We always make sure to fill our casks when fermentation is next to complete in the fermenter, i.e. after the bubbling stops in the blowoff. The act of filling the casks agitates the yeast enough to continue fermentation for us -- but not too much. It's not scientific, but it works 99.9% of the time. We also throw whole leaf hops into the casks when we fill them.

Where I went wrong was when I dry-hopped my cask, I also threw some caraway seeds into it (it was a rye ale). The caraway seeds acted as nucleation points for the CO2 as it continued to ferment. Combining that undissovled CO2 with the higher temperature (in which case CO2 naturally starts to come out of solution), and the pressure caused an explosion.

I'm not sure if you dry-hopped yours, but the hops can also provide nucleation points for the CO2 to come out of solution, though probably not as many as hundreds of tiny little seeds.

So next time, be aware of your visible fermentation when you fill your casks, the addition of nucleation points and temperature and you should be fine.

The beer in casks is living and thus unpredictable, but with some trial (by fire in your case), you should be able to control it pretty easily.