What's up with my blowoff valve?

[Mountvillainy]

I'm brewing my first-ever batch of beer, and I'm using a premixed wort (stout) so that if something goes wrong I know its in my fermentation process and not my recipe. Well, I'm brewing in a plastic bucket, and I got home last night to find that a pretty large amount of wort had bubbled up through the airlock and onto the top of the bucket. I cleaned everything as best as I could and rigged up a blowoff tube by cutting a slit into my siphoning tube and sticking it down into the top of the airlock, then running it into a container of sanitized water.

This morning I got up to find that my blowoff tube had indeed held up and was channeling a slow but steady stream of foam into my receptacle, with spaces of air in between. However, the lid of my bucket is bulging as if it's under high pressure and a very tiny amount of beer has even leaked out from under the lid in a couple of spots--I don't believe it was doing this before I attached the tubing. It appears to be doing this thing where the air and foam move slowly through the tube, while pressure builds in the bucket until it approaches "critical mass" and quickly shoots air and foam through the tube for a few seconds. Right before this happens, an extremely small quantity of beer tends to escape from underneath the lid. After everything blasts through the tube for a few seconds, it slows back down and starts this process over--this happens every few minutes. The tube and airlock don't appear to be obstructed in any way, air and foam are moving through the tube continuously, and the seal on the lid seems airtight until a little foam forces its way out right before air starts shooting through the tube.

Is this at all normal? Is it unsafe to leave my beer fermenting under these conditions? Will it damage my brew if I periodically crack the lid to relieve some of the pressure? Any ideas what can be causing this, or what might fix it? My only theory is that my tubing is too narrow and I need to need to go to a wider tube that fits over the airlock, not down in it...but I'm a total noob, so what do I know? Any help is appreciated.

 

[scoundrel]

I'm brewing my first-ever batch of beer, and I'm using a premixed wort (stout) so that if something goes wrong I know its in my fermentation process and not my recipe. Well, I'm brewing in a plastic bucket, and I got home last night to find that a pretty large amount of wort had bubbled up through the airlock and onto the top of the bucket. I cleaned everything as best as I could and rigged up a blowoff tube by cutting a slit into my siphoning tube and sticking it down into the top of the airlock, then running it into a container of sanitized water.

This morning I got up to find that my blowoff tube had indeed held up and was channeling a slow but steady stream of foam into my receptacle, with spaces of air in between. However, the lid of my bucket is bulging as if it's under high pressure and a very tiny amount of beer has even leaked out from under the lid in a couple of spots--I don't believe it was doing this before I attached the tubing. It appears to be doing this thing where the air and foam move slowly through the tube, while pressure builds in the bucket until it approaches "critical mass" and quickly shoots air and foam through the tube for a few seconds. Right before this happens, an extremely small quantity of beer tends to escape from underneath the lid. After everything blasts through the tube for a few seconds, it slows back down and starts this process over--this happens every few minutes. The tube and airlock don't appear to be obstructed in any way, air and foam are moving through the tube continuously, and the seal on the lid seems airtight until a little foam forces its way out right before air starts shooting through the tube.

Is this at all normal? Is it unsafe to leave my beer fermenting under these conditions? Will it damage my brew if I periodically crack the lid to relieve some of the pressure? Any ideas what can be causing this, or what might fix it? My only theory is that my tubing is too narrow and I need to need to go to a wider tube that fits over the airlock, not down in it...but I'm a total noob, so what do I know? Any help is appreciated.

Everything is fine and it sounds like you have a rockin fermentation. Bulging lids are not uncommon. You can crack the lid but I wouldn't bother. As long as the CO2 can escape, you'll be fine. You just don't want the tube to clog. Keep an eye on it. As long as its flowing you won't have a problem.

Also remember, CO2 is a barrier and will protect your beer, so opening it isn't an issue. You just want to keep things from falling in. That being said people have dropped things in their beer and it still turns out fine. If me memory serves someone just recently dropped a pen in their beer and all is well. Relax its gonna be good.

 

[Mountvillainy]

Sweet! I guess it's probably normal for beginners to think everything is going to ruin their batch. So the little bit of beer escaping from under the lid isn't a problem either?

 

[scoundrel]

Sweet! I guess it's probably normal for beginners to think everything is going to ruin their batch. So the little bit of beer escaping from under the lid isn't a problem either?

No. A bit messy, but no.

 

[kh54s10]

You might check the bottom of the airlock to make sure all the openings are clear.

I had one airlock that popped out, I cleaned it and re-installed and it popped out again. On closer inspection they never removed the excess plastic at the tip so it was sealed closed, no air could pass through.

Obviously yours will pass co2 but it may be partially blocked causing the pressure buildup.

 

[TomSD]

You might check the bottom of the airlock to make sure all the openings are clear.

I had one airlock that popped out, I cleaned it and re-installed and it popped out again. On closer inspection they never removed the excess plastic at the tip so it was sealed closed, no air could pass through.

Obviously yours will pass co2 but it may be partially blocked causing the pressure buildup.

Some of them come with a little x of plastic across the hole. No idea why they would do that but it does tend to block up if used with a blow-off. You can safely cut the end off if that is the case though and solve the problem.

 

[Butter]

That's why I have like 10 airlocks scattered about. They're cheap enough to grab a couple everytime I go to my LHBS. When one clogs, I grab another one that's sitting around.

 

[Mountvillainy]

Looks like I was wrong to be worried, my setup went nuts like that for the rest of the day and had mellowed out considerably by the time I went to bed. Now it's steadily putting out a bubble about every second and a half, which I assume means I still have pretty decent fermentation going on.

 

[Hang Glider]

At what temp were you fermenting? sometimes it gets really strong when it's too warm - which is not really a good thing...

You need to investigate your yeast strain, then consider keeping your fermenter at the low end of that scale, because active fermentation increases the temp of your wort from 5-10F above ambient - I've even read someone claiming 16F...

It's a little late for this batch, but something to consider.

welcome to HBT!