Making a Blow-Off Tube

Not long ago one of our members had a major blow-up while brewing an Imperial Stout; the fermentation lock overflowed, and the lid to the secondary eventually blew off sending foam all over the room.

I thought about that recently - I was brewing a White Stout, with an O.G. of 1.062, and since I'd done a yeast starter by the next morning after brewing the fermentation lock was already bubbling. By lunchtime, it was bubbling rather violently. The temp was 72 F, so it was perfect for the yeast, and I guess that there were just so many sugars to eat that they were going crazy. Early in the afternoon I noticed that the fermentation lock had filled up with wort, and a problem was brewing (so to speak).

Grabbing another fermentation lock, I drove to the local hardware store and purchased five feet of tubing that was 3/4" on the outside, 1/2" on the inside diameter. It was heavier than it needed to be, but that's what they had and with the primary explosion eminent, I took it. It fit snugly over the interior nipple of the fermentation lock. Dashing back home, I filled my bottling tank with about six inches of water, swapped the modified fermentation lock with the one on the primary, and put the other end of the tube in the water. I also put a towel around the fermentation lock just in case, but it turned out not to be needed.

The only problem was that the tube was so heavy that it was pulling the fermentation lock over and out of the primary fermenter lid, so I ran to the kitchen, rifled through the pantry, and grabbed a jar of Prego sauce. It was perfect to put underneath the bend of the hose to solve the problem. After that, all of the blow-off went into the water in the bottling tank. Once it calms down, I'll put the fermentation lock back together and go back to the standard configuration. For now, though, this has been a brew-saver!

About 24-36 hours later, the bubbling had slowed down to a regular pace and I switched to another fermentation lock for everything to proceed normally. In the future, I'll have this rig standing by any time I brew a higher-gravity beer.