Fermentation explosion

[MasterLaz]

Help.....I have a five gallon carboy of True Brew Porter in the laundry room that started fermentation yesterday. It has been working great, fermenting out of the top of the airlock all morning. Just a little while ago, I went to check it when I found it had blown the stopper and airlock off of the carboy. The explosion was all over my wife's laundry room, covering two walls. After about thirty minutes of cleaning I finally got it all back together. What have I done wrong and is this going to happen again? The airlock seems to be working fine.

 

[McGarnigle]

What do you mean 5 gallon carboy? Is this a 5g batch in a 5g carboy? If so, that's the problem.

 

[MasterLaz]

Good catch, thanks....it is a 6 gallon carboy with a 5 gallon batch

 

[nu2brewing]

For sure, if you put a 5 gallon batch in a 5 gallon carboy, that's trouble. You need to transfer it to at least a 7 gallon fermenter. You need the head space so your feverish fermentation doesn't pop the airlock.

Trust me I did that same with a batch of Apfelwein, it blew the airlock off all over my dining room table and floor. Oops! Live and learn.

 

[iijakii]

You need to get a blowoff tube, search the forums for examples.

 

[ChillWill]

+1 blow off tubes.

I've got a stout on the go with OG of 1.050 and it using Nottingham yeast it went nuts, kicked out plenty of krausen through blow off tubes, although that's 2 gallon batch in 2x 1 gallon carboys (which hasn't been a problem for previous batches). The fermenters felt warm while doing it so I moved it somewhere cooler to calm down. In future I'll keep it in ambient 60-65F as I think it was high 60's where it was initially.

 

[burglar]

I've had that happen on a few high gravity beers - I learn slow. The krausen (foam) will plug up the airlock, pressure builds, and eventually it fires off the rubber stopper like a missile.

As stated above, using a bigger fermenter or building a blowoff tube are the two easiest fixes, and you might want to check your fermentation temp too.

 

[RM-MN]

For your next brew session, set your carboy in a plastic tub or laundry basket and put cold water in the tub to keep your brew cool for the first 2 or 3 days, adding chunks of ice or pop bottles filled with frozen water. The character of your beer is set by the fermentation temperature during that really active phase and by keeping it cooler, you will get a better flavor and less chance of washing the walls too.

 

[jtkratzer]

Are there any particular styles of beer or yeast that this is more common with? I've only done two batches in carboys, a 6.5 gallon, and neither has come close to touching the airlock, let alone blowing it off.

 

[MarkSheffield]

It happened to me once. Just before the divorce.

 

[robtotten]

Wheat beers in my experience are more susceptible. Also anything pitched on an existing yeast cake or huge starter.

 

[ChillWill]

Are there any particular styles of beer or yeast that this is more common with? I've only done two batches in carboys, a 6.5 gallon, and neither has come close to touching the airlock, let alone blowing it off.

I think it's mostly down to the yeast and if it is pitched properly. Rehydrated nottingham went vigorously for me, but a batch I did where I rehydrated wrong (too much water) took a while to set off.

I think the amount of trub in the beer may also affect, I obviously didn't do a great job of whripooling etc with my stout and ended up with some muddy paste like stuff with hops in it at the top of my fermenter whereas the normal foam didn't really get that high and subsided instead of sticking

 

[iijakii]

Are there any particular styles of beer or yeast that this is more common with? I've only done two batches in carboys, a 6.5 gallon, and neither has come close to touching the airlock, let alone blowing it off.

A general rule of thumb for most people is that high OG beers will have lots of krausen. But krausen formation variates from your protein content, yeast, temperature, water profiles, down to even the moon-phase. It's hard to guess. Best thing is to keep an eye on it and/or start with a blowoff everytime.

 

[LiquidLunch5211]

It happens +1 add blow off tube. Search forum there are pictures around that will show an example. Good luck

 

[Hamada]

Fermcap S will stop blow-offs as well. I didn't like using a blowoff tube because my cat would get into the bucket of sanitizer and track the yeasty mess all over my basement. Since I started Fermcap in the fermenters I haven't had a single blow-off.