An air-tight airlock?

[Howareya]

(Sorry for the silly question!)

Is an airlock meant to be air-tight?

I ask because my to-be beer is currently fermenting in the bucket.

The bucket seems to be under pressure, as the plastic lid is being pushed upwards. There's some froth in the air lock, and a little liquid too.

I'm guessing the airlock should be letting out the pressured gas, not keeping it inside. Am I wrong?

Howareya.

 

[hercher]

You are correct, the airlock should be letting pressure out. It sounds to me like it might be clogged. Carefully remove the airlock -- I'd suggest wrapping a clean cloth around the base as you remove it to catch any krausen that wants to explode out -- and clean it. Make sure it isn't clogged and put it back in. You will want to check periodically to make sure it doesn't get clogged again, or insert a blow-off tube in its place.

 

[beergolf]

Look into rigging up a blow off tube. It is as simple as putting some tubing over the center portion of the airlock. Make sure you cut the little X part that is on the stem of the airlock. Then run the tube into a small container of sanitizer.

I start every brew with a blow off tube, just in case. Every fermentation is different and some just go crazy.


here is a pic in this thread.


https://www.homebrewtalk.com/f39/emergency-blow-off-tube-112617/

I would recommend no putting the container on top of the bucket but on the floor so you don't get suck back.

 

[BamaRooster]

You need to get a blow off tube hooked up like beergolf suggests...if the pressure gets high enough in the vessel it will blow the top off and that is a mess you will never ever forget.

 

[dbhokie]

+1 Blow off tube, easy and it can take harder fermentation. If you have a very strong fermentation with a high gravity beer (when your tossing a crapton of yeast in there), and you just have a little airlock on it, you might end up with a blown lid and krausen and beer all over your floor.

 

[BamaRooster]

+1 Blow off tube, easy and it can take harder fermentation. If you have a very strong fermentation with a high gravity beer (when your tossing a crapton of yeast in there), and you just have a little airlock on it, you might end up with a blown lid and krausen and beer all over your floor.

or all over the ceiling and walls!

 

[Howareya]

Thanks all, I'll look into doing a blow off tube.

What I did today was lift the plastic lid off the airlock, and leave it resting on the rest of the plastic mechanism.

I presume this is not a great solution?

BTW, this is my second brew. In my first brew I didn't even put the airlock on (as I didn't know what it was for!) and I had the hole in the lid just left there open. It worked out ok thankfully.

 

[krazydave]

If it's a 3 piece airlock, they usually have little cross strainers on the bottom where you stick it into your fermenter. I tend to cut those little crosses off to prevent them from clogging.

I'd much rather have krausen oozing from my airlock that an exploding fermenter.

Ideally though, you should set up a blowoff tube for the first few days until the krausen drops, then the airlock should be fine.

 

[HibsMax]

I always start with a blow off tube, after reading these forums, but I still get what the OP is seeing....as well as bubbles. I have the often mentioned converted airlock in place with a piece of 1/2" ID vinyl tubing going to a 1 gallon growler with star san BUT my fermentation bucket lid is still bulging. This has happened on more than one occasion. No blockages. Still bubbling in the sanitizer. If I gently press down on the lid I can force all the CO2 out into the sanitizer solution but after a while the lid is bulging again. I don't quite understand why that is though. I would have thought it would take less energy to flow through a 4' pipe into some liquid than press a plastic lid up into the air.

 

[KevinW]

Thanks all, I'll look into doing a blow off tube.

What I did today was life the plastic lid off the airlock, and leave it resting on the rest of the plastic mechanism.

I presume this is not a great solution?

BTW, this is my second brew. In my first brew I didn't even put the airlock on (as I didn't know what it was for!) and I had the hole in the lid just left there open. It worked out ok thankfully.

Actually that is a great solution! As long as the lid is resting on the top of the bucket you should still have a positive pressure to keep the oxygen out!

Carbon Dioxide is heavier than air so it will form a "protective" layer on top of your beer!

One question, did you put any liquid in your airlock after you installed it?

 

[Howareya]

@KevinW No, I didn't put any liquid in there. I saw from a photo today that it seems like someone had just some water in there. So I take it I missed the trick of how to use it?

That's the damn trouble of a beginners kit with all these things coming with it, without even an explanation of what each thing is. Oh well, it's part of the learning experience.

 

[KevinW]

Well keep at it, sounds like you are learning as you go so that is all that is needed!

This forum is a great place to find out how to do things and you are here!!

Good luck and keep asking questions!

 

[Howareya]

Yup, this community is fantastic. I agree.

 

[HibsMax]

As I was walking past my fermenters a minute ago I was looking at the two that have bulging lids - they are also still bubbling several times a minute - it occurred to me.......a bulging lid *could* be seen as a good thing, maybe, I think. My thinking is that a tight lid means you have a good seal. If you didn't then the CO2 would just squeeze out through the leaks. Not sure if that is scientifically accurate but just a thought that occurred to me and I remembered your post.