Airlock not coping in fermentation

[MikeBusby]

I have a oatmeal stout currently fermenting and the airlock cannot cope with the amount of CO2 being produced (see below). My first question is (1) what can I do right now to stop this batch getting too messy, and (2) how can I avoid this in the future, especially as I was planning on trying a kveik yeast at the weekend!

 

[Gerryjo]

Fit a length of tubing from the airlock by removing the cap and place in a bottle with sanitiser or cheap vodka.

 

[An Ankoù]

Take the bung out and cover the cap with a medium or large freezer bag held in place with a rubber band. When the fermentation subsides, replace the airlock.
If it were me, I'd remove the bung and cover the hole with a clean tea towel folded double, but I know some people might think that;s an infection risk in spite of the fact that open fermentation has been going on for decades, if not centuries.

Edit: You seem to have plenty of headspace in that fermenter. I'm surprised it's foaming over.

 

[MikeBusby]

That is very satisfying to hear and watch! Will this be able to cope like this for any amount of CO2? As I said, I am planning on using a kveik at the weekend.

New video by Mike Busby

 

[MikeBusby]

Take the bung out and cover the cap with a medium or large freezer bag held in place with a rubber band. When the fermentation subsides, replace the airlock.
If it were me, I'd remove the bung and cover the hole with a clean tea towel folded double, but I know some people might think that;s an infection risk in spite of the fact that open fermentation has been going on for decades, if not centuries.

Edit: You seem to have plenty of headspace in that fermenter. I'm surprised it's foaming over.

I was surprised too. However, now I have the overflow tube snuggly fitted into the bung for the airlock, is there any reason why I should not using the system all the time, rather just when it get particularly active?

 

[Hazelwood Brewery]

Don’t worry about it we all have this from time to time and you can expect it with big beers and aggressive yeasts.

Google “blowoff tube”

 

[Gerryjo]

I was surprised too. However, now I have the overflow tube snuggly fitted into the bung for the airlock, is there any reason why I should not using the system all the time, rather just when it get particularly active?

Use it all the time if you want. It does have a soothing effect listening too the bubbles popping in the bottle.

 

[An Ankoù]

I was surprised too. However, now I have the overflow tube snuggly fitted into the bung for the airlock, is there any reason why I should not using the system all the time, rather just when it get particularly active?

No reason at all. It's just a big airlock after all. I often think these little airlocks are really made for demijohns of wine. If you look at, for example, a Speidel airlock, you'll see it's much bigger in every respect.

 

[MuckyNeighbour]

Fit a length of tubing from the airlock by removing the cap and place in a bottle with sanitiser or cheap vodka.

Great piece of advice. My stout was behaving like Mt Vesuvius and I was clearing the airlock at least twice a day. Tried this tip and it’s totally sorted. No idea how it works (physics was never my strong point) but I don’t care!

 

[YeastFace]

Darker beers always seem to "jump out" of the fermenter for me.

A blow-off tube placed into a bottle of starsan is yer man.

 

[Clint]

I only ever use a blowoff tube and bottle.

 

[MuckyNeighbour]

curious about why you need to feed the tube into sanitiser: the airlock is still in place to protect the beer so I just fed the tube into an empty bottle

 

[anders]

curious about why you need to feed the tube into sanitiser: the airlock is still in place to protect the beer so I just fed the tube into an empty bottle

When fermentation subsides and/or temperature drops, you could have negative pressure. Better having sanitised water or vodka sucked back into the brew than oxygen

 

[Cheshire Cat]

curious about why you need to feed the tube into sanitiser: the airlock is still in place to protect the beer so I just fed the tube into an empty bottle

An empty bottle is not an airlock a bottle with liquid is.

 

[Druncan]

With a blow off tube, you can also salvage CO2 I use 20l wine bags and a vigo tap. I re-introduce this when kegging and for no-chill.

 

[MuckyNeighbour]

An empty bottle is not an airlock a bottle with liquid is.

But my tube is attached to the top of the airlock with the other end in an empty bottle. The airlock is still doing it’s job but, somehow, the beer is no longer bubbling through it. Essentially I have a standard sized airlock with an enormous “chimney”

 

[MuckyNeighbour]

When fermentation subsides and/or temperature drops, you could have negative pressure. Better having sanitised water or vodka sucked back into the brew than oxygen

When fermentation subsides and/or temperature drops, you could have negative pressure. Better having sanitised water or vodka sucked back into the brew than oxygen

so you’ve removed the s shaped airlock and replaced it with your own version? I attached a tube to the top of the airlock, with the other end in an empty bottle.

 

[Cheshire Cat]

Fill the bottle with water not sanitiser or vodka, remove your existing airlock and push the tube through the grommet. I would however sanitise the bottle first as you would an airlock.

 

[Clint]

Most reasons for swapping out the standard airlock is because the fermentation is very lively and overwhelms it. This saves having to clean up a right mess.

 

[Chippy_Tea]

Get yourself one of these bad boys -
https://www.thehomebrewforum.co.uk/threads/super-major-airlock.88765/post-931590