Air leak with bung

[O-Ale-Yeah]

I have 2 glass carboys in day 4 of fermentation. One is bubbling with a blow-off tube like nuts! The other sits quietly unless I put some pressure on the bung and then it bubbles through the blowoff tube. I always place some Starsan soaked cellophane around the bung and then tape it down because the bung don't stay in place. It's apparent that there is an air leak through the side of the bung under the cellophane.

My question is, do I leave it or pull off the tape and apply a new piece of Starsan soaked cellophane and tape?

I think next time, I'll skip the 1/2 inch blow-off tube and bung and just put a 2 inch blow-off tube directly on the carboy.

 

[RPh_Guy]

The bung should be able to stay by itself, here's how:
Make sure both the bung is dry and the inside of the glass where the numbers touches. Dry it with a clean paper towel.

 

[O-Ale-Yeah]

The bung should be able to stay by itself, here's how:
Make sure both the bung is dry and the inside of the glass where the numbers touches. Dry it with a clean paper towel.

Thanks.

The question was, fix it or leave it?

 

[RPh_Guy]

I would fix it.

 

[O-Ale-Yeah]

I would fix it.

Ok thanks, I pulled off the cellophane, tape, sprayed it with starsan, dried it off with a clean paper towel, and taped the bung down.

 

[RM-MN]

It isn't critical whether the bung is sealed or not. Bubbles in the airlock are for entertainment purposes only. The bung and airlock are only there to keep bacteria from falling into the beer. Sealed or not, they do this just fine. I have one fermenter with no airlock at all, just a piece of Saran wrap taped over the opening with one side loose so it lets the excess CO2 out.

 

[RPh_Guy]

The bung and airlock are only there to keep bacteria from falling into the beer.

A good seal helps to keep out oxygen.

 

[ApolloSimcoe]

Star San is slippery. I have heard that some brewers have wiped the bung and inside neck of the carboy with rubbing alcohol. The rubbing alcohol sterilizes the area while also causing evaporation of the star san. The bung will then not slide up. Note: I have never actually tested this myself

 

[O-Ale-Yeah]

Thanks for all of the good tips. I did put the bung in wet with starsan last week. From now on I'll definitely let it dry and wipe it with alcohol.

 

[RM-MN]

A good seal helps to keep out oxygen.

With only a small hole and continuous flow of CO2 coming out not much oxygen is going to get in nor will bacteria. If you had a carboy with an open top, then you would need to worry. A leak around the bung? No problem.

 

[RPh_Guy]

With only a small hole and continuous flow of CO2 coming out not much oxygen is going to get in [...] A leak around the bung? No problem.

Gasses diffuse/effuse quite rapidly.
Do you know the average speed of a molecule of O2 gas at fermentation temperature?

Bottom line:
For those of us that want to protect our beer from oxygen, a "small" leak is too much.

 

[eddie]

You're worrying yourself into failure, man. Just let it be.