Stoppers and Airlocks

[rbankert]

I received a 3-piece airlock with my equipment kit which was with a 5-gallon carboy. I recently purchased a 6-gallon carboy and found that when I went set up the airlock on the 6-gallon carboy, the rubber stopper would blow off after only a minute.
I then transfered the wort back into the 5 gallon carboy, and the stopper was fine. Are there different sizes for 5 and 6 gallon carboys??

 

[Sasquatch]

There may in fact be a size difference, but even if there isn't, I have found that "identical" carboys occassionally have a shape to the lip that just doesn't really hold stoppers all that well. I have one that I have to push the stopper well past the top of the carboy, which I don't like to do. Even stranger, it is one particular stopper (same size as all the others I have) which just refuses to sit. So.... my advice is to hit the hb shop, see if they have a slightly bigger one, but even if they don't, buy a different stopper made from different material if possible, and see how it works.

 

[pop_shots]

I received a 3-piece airlock with my equipment kit which was with a 5-gallon carboy. I recently purchased a 6-gallon carboy and found that when I went set up the airlock on the 6-gallon carboy, the rubber stopper would blow off after only a minute.
I then transfered the wort back into the 5 gallon carboy, and the stopper was fine. Are there different sizes for 5 and 6 gallon carboys??

carboys use blowoff tubes

 

[david_42]

Carboys have different sized openings, depending on the manufacturer. Most of the time a #6 works, but not always. You'll have to get another stopper and airlock for the larger carboy.

 

[El Pistolero]

Are there different sizes for 5 and 6 gallon carboys??

My 6.5 gallon carboy used a size 6.5 stopper, and my 5 gallon uses a size 7. One think that will help with the stopper popping out is make sure it's dry before you use it.

 

[bikebryan]

carboys use blowoff tubes

Danger, Will Robinson, Danger.

Blanket statements can be dangerous. You don't ALWAYS need a blow off tube if you primary in a carboy. It depends on your batch size vs the size of the carboy!!!