Sealing a blow off tube

I have a 6.5 glass carboy and a 1.25 inch blow off tube. The tube fits in to the top of the carboy but it doesn't form a tight seal. Does anyone have any suggestions? I plan on brewing a Double IPA this afternoon and want to make sure I don't have an airlock explosion!

Thanks.

Do you have an airlock? Normally they have a plastic bung that fits in the mouth of the carboy. You could enlarge that to snugly fit the blow off tube. Then just get another plastic bung from the local brew store (can't imagine it would be more than a buck at most). That would be the quickest and easiest way IMO.

I thought the tubing size was 1" for fitting a blow off tube directly to a carboy. I just have my blow off tube hook up to the inside tube of my airlock. Makes it so whether i'm using a regular plastic fermenter or a carboy I can always have the option for a blowoff tube should i need one and don't have to keep several sizes of tubing. If you want to do the airlock method I use, you would just need 1/2" tubing.

I cut the hole in my fermenting bucket a tiny bit larger than the diameter of the blow off tube. I take about 12 to 18 inches of plastic wrap (Seran wrap, etc) and fold it in half (length-wise) 3-4 times. I end up with a strip of wrap about 1/8 to 1/4 inch thick. Wrap that around one end of your tube and put it in the hole. It will seal it nicely, and I'm pretty confident that plastic wrap is sanitary. No problems with me in the two years doing this.

I don't know exactly how much space you are referring to...

If it is close... An airtight seal is unnecessary at this point. The beer will be out-gassing so much it shouldn't matter much. When fermentation slows just switch to an airlock.

I agree with what's been said above, but if it really bothers you you can wrap some plastic wrap around the top of the carboy and tube.

Sanitize a rubberband and put over the tubing?

mullimat said:

I thought the tubing size was 1" for fitting a blow off tube directly to a carboy. I just have my blow off tube hook up to the inside tube of my airlock. Makes it so whether i'm using a regular plastic fermenter or a carboy I can always have the option for a blowoff tube should i need one and don't have to keep several sizes of tubing. If you want to do the airlock method I use, you would just need 1/2" tubing.

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I don't think this is a good idea, unless you are really careful about preventing any of the break from getting into the fermenter (and don't dry hop etc.). Having tubing only 1/2" could lead to a clog if a chunk of something (hop/gunk) got into that tubing and clogged. I think the reason many people use blow off tubes is due to the restriction of the typical airlock. It's not that the airlock couldn't just leak all the gunk out and around the bottle (this would be safe but a PITA to clean up, its the fear that it could clog due to the small opening. Having a 1" (or larger if wide-mouth bottle) tubing all but ensures you will never have a problem if the krausen gets too high.

While having larger tubing will definitely prevent clogging and thus will be better, I have never had a problem with clogging with my setup. I just think it's a good option for people that use both plastic fermenters and carboys and don't want to have to deal with keeping multiple sizes of tubing around. And to fix the possibility of clogging even further with the airlock i cut the bottom off the airlock.

I had the same problem with my 6 1/2 g carboy. There just wasn't a "perfect-sized" hose to fit the neck. I took a drilled universal carboy bung and completely hollowed it out with an exacto knife. I ran the end of the 1.25 inch hose under hot water to make it pliable and then pushed it into the carboy bung. I'm not a 100% satisfied with it, but it's worked so far. Make sure it's dry and give it a good solid push into the carboy.

Disclaimer: Pressure from fermentation hasn't dislodged it, but moving the hose will.

Glad Press and Seal Wrap!

7Enigma said:

I don't think this is a good idea, unless you are really careful about preventing any of the break from getting into the fermenter (and don't dry hop etc.). Having tubing only 1/2" could lead to a clog if a chunk of something (hop/gunk) got into that tubing and clogged.

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I think usually you don't want to dry hop until long after explosive fermentation is complete (2 - 3 days before bottling).