Carboy Caps instead of stops

I am using a carboy cap in my 6.5 gallon carboy as a primary. The airlock stopped bublying after 2 days of aggressive fermentation. When I twist the cap a little, the airlock bubbles for a while. I am thinking there might be a leak around the cap. Does anyone else use a carboy cap during fermentation? Anyone have one leak on them? It probably isn't a big deal, but I am a bit concerned with it letting things in if it is letting c02 bypass the airlock.

You are probably just putting down pressure and re-leasing some gas, RDWHAHB as long as the cap fit on the neck tight your allset, your fermentation is probably slowing down.

You should not have a problem but if it stresses you out take a cable tie and tighten it around the base of the cap for a good seal.

Nothing is getting in there. As long as it is covered you're good. Some people don't even use airlocks. They just stick some foil over the top. They only way things can get in is if they fall in from above. They can't just fly in around the cap.

I use (and love) carboy caps, because they make transferring beer a lot easier after fermenting.

I hate the little carboy cap caps that come with them. You know, the little white doohickeys that are supposed to cap off the tube if you're not using them. Yeah, those. I hate those little ****ers. I'm always knocking them off so they roll around the basement floor and then losing them.

I don't use an airlock for primary anymore. I stick a dial thermometer with a 12" probe down through one hole in the carboy cap and cover the other hole with foil. The dial of the thermometer covers the hole nicely, so I don't have to worry about nasties finding their way into my beer.

Remember, people. Microbes and wild yeast DO NOT HAVE LEGS, or flippers, or fins, or any other means of locomotion. They drift on the air, usually attached to dust. If dust can't fall into your fermenter, neither can microbes.

jds said:

Remember, people. Microbes and wild yeast DO NOT HAVE LEGS, or flippers, or fins, or any other means of locomotion. They drift on the air, usually attached to dust. If dust can't fall into your fermenter, neither can microbes.

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I always pictured them with little helicopter rotors.

I use carboy caps for primary, and I do use a big zip tie around them to keep them tight, as they will leak.

I changed the carboy cap for stopper, just to see if it would continue to bubble with a stopper. It has been bubbling away for about 15 hours now, so I guess it was leaking. I guess contamination risk is low even if the cap is leaking, but I like to see when the bubblying slows down so I know when to try a hydrometer reading.

MA_Brewer said:

I use carboy caps for primary, and I do use a big zip tie around them to keep them tight, as they will leak.

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Which only matters if you're using them to start siphons. If you're only using them in place of stoppers, read the three posts before yours, you'll hopefully start to realize a very important fact...

Bacteria fall down.

They don't climb, walk, run, sprint, jog, drive, hike, bike, hover, levitate, or move in any other way than floating on the breeze.

If you follow basic sanitation guidelines, use a blowoff for the first 3-7 days of fermentation, then replace the blowoff with sanitized tinfoil, you will never ever ever ever ever get an infection, or any other off flavor from unwanted bacteria. Plus you'll save quite a bit of money in the long run on airlocks, stoppers, and vodka/sanitizer.

If you do use them for siphoning, a rubber band works great. Keep in mind that most of these caps won't fit on better bottles nearly as well as they do on glass carboys.

Edited: Just wanted to stress that my post here wasn't meant to be rude, or as a personal attack against MA_Brewer. I only stress the bacteria fall down bit because so many people don't realize how useless a stopper/airlock can be.

llazy_llama said:

Which only matters if you're using them to start siphons. If you're only using them in place of stoppers, read the three posts before yours, you'll hopefully start to realize a very important fact...

Bacteria fall down.

They don't climb, walk, run, sprint, jog, drive, hike, bike, hover, levitate, or move in any other way than floating on the breeze.

If you follow basic sanitation guidelines, use a blowoff for the first 3-7 days of fermentation, then replace the blowoff with sanitized tinfoil, you will never ever ever ever ever get an infection, or any other off flavor from unwanted bacteria. Plus you'll save quite a bit of money in the long run on airlocks, stoppers, and vodka/sanitizer.

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I agree with your whole statement but believe the saving moeny on airlocks and vodka are mute points. I mean we're talking a 50 cent airlock, 30 cent stopper, bottle of 5 dollar vodka to last FOREVER!

IrregularPulse said:

I agree with your whole statement but believe the saving moeny on airlocks and vodka are mute points. I mean we're talking a 50 cent airlock, 30 cent stopper, bottle of 5 dollar vodka to last FOREVER!

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I have to disagree with you on the vodka part. I used vodka for a while, and found myself refilling airlocks after 2-5 days on average. Vodka has a tendency to evaporate rather quickly. Granted, I tend to have some vodka on hand anyway, but that's beside the point if frugality is the goal. I also had it pointed out to me by some of our Canadian brew-brethren that Vodka can be very expensive in some places.

Also, if your LHBS sells airlocks for 50 cents and stoppers for 30, please tell them to set up a website! I don't have a LHBS in my area, so I have to order online. The cheapest I've seen airlocks go for is $1.50 and stoppers for about the same.

Edited: also, vodka (or sanitizer, just whatever you choose to use in your airlocks) tends to go much farther in S-type airlocks as opposed to 3 pieces. More bang for your buck in those S-types.

None of my caps fit right on any of my carboys. They sit on the shelf.

llazy_llama said:

Which only matters if you're using them to start siphons. If you're only using them in place of stoppers, read the three posts before yours, you'll hopefully start to realize a very important fact...

Bacteria fall down.

They don't climb, walk, run, sprint, jog, drive, hike, bike, hover, levitate, or move in any other way than floating on the breeze.

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I guess I should have stated that I am not all to concerned about bacteria getting in under a lose carboy cap - rather the airlock or blowoff tube won't bubble if it is lose. That is important to me to gague fermentation. I often times ferment colder than "normal", and fermentation can take a while.

llazy_llama said:

Also, if your LHBS sells airlocks for 50 cents and stoppers for 30, please tell them to set up a website! I don't have a LHBS in my area, so I have to order online. The cheapest I've seen airlocks go for is $1.50 and stoppers for about the same.

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If you buy stoppers by the pound you can get them pretty danged cheap.

Maybe homebrew clubs could consider buying a pound each of common sizes and splitting the cost up with the members.

I’m short for head space.

Newbie and want to bump this:

I wanna quote, but don’t want to start any static so…

I call bs (on nasties don’t crawl and they only fall down). Air drafts, wind, fans, heck temp changes can cause air to rise up. Those little nasty’s can surf the wave. I might be a little anal but I burp my Tupperware. In other words, I wouldn’t trust my hard work and $$$ on sanitized foil and if there is a leak in the airlock then there’s a chance… why else would air locks be designed as a one-way road? Even when your love is burping, a release of pressure causes a counter pressure or suck back… sucking in whatever is around the neck of the carboy. So, actually, the bung-in-the hole w/3 piece is almost better granted you sanitize the area before removing. But this is a little extreme, no? I’m not that anal, but…

I bring this up cause I just adopted two carboy caps and they’re loose… this disturbs my ocd. I’m thinking maybe a boil for 20 seconds and then quick fit, let sit, and it should tighten up around the neck. Anyone try this?

discooby said:

I call bs (on nasties don’t crawl and they only fall down). Air drafts, wind, fans, heck temp changes can cause air to rise up. Those little nasty’s can surf the wave.

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I think you're right about this. Some people say they fall downward - but how did they get UP in the first place, if not for rising on air currents?

discooby said:

I bring this up cause I just adopted two carboy caps and they’re loose… this disturbs my ocd. I’m thinking maybe a boil for 20 seconds and then quick fit, let sit, and it should tighten up around the neck. Anyone try this?

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You didn't say whether you are using the caps with glass carboys or Better Bottles. They don't fit Better Bottles very well, but I've found a way to make them airtight on my BB's. I insert one of these under the cap:

http://www.bargainfittings.com/index.php?route=product/product&path=36_42&product_id=105

Unfortunately, these are just barely big enough to work (IIRC these are 1 7/8 inch diameter - 2 inch would be ideal) , so you have to be careful to get them centered. I lay one on top of the BB mouth and center it, then place the orange carboy cap over the top and press it down taking care not to move the gasket. This gives me an airtight seal.

I’m using glass carboys so not sure the gasket would work. I’m still leaning towards boiling them and then sticking them on. We used to do that with mouth pieces to form to the mouth and teeth; though I’m sure the caps are a completely different plastic.

If I have success then I’ll post back. If it doesn’t work then I’ll check out the gasket as that may actually work. Thanks for the idea! Cheers

Most of my carboy caps don't fit snugly, not concerned about it.

If you need to see how fermentation is proceeding, can't ya just look at the wort inside the carboy?

kanzimonson said:

Most of my carboy caps don't fit snugly, not concerned about it.

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Why not concerned? I like your post… it gives me happy thoughts EDIT... in the sense that my caps might work fine.

kanzimonson said:

If you need to see how fermentation is proceeding, can't ya just look at the wort inside the carboy?

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I’m short for head space as I just built a 32dd ferment chamber so looking at my new carboys isn’t an option… yet (or until the winter). Webcam is on the list, but until I figure out how (lighting, etc) it’ll have to wait.

But!!! I do want to add: I’m doing a yeast starter in hopes of freezing 16ml vials (thanks FlyGuy) so I’m using foil on my starter w/a stir plate. But, you all know why foil instead of a stopper… it’s a starter.

DownRightAft said:

I am using a carboy cap in my 6.5 gallon carboy as a primary. The airlock stopped bublying after 2 days of aggressive fermentation. When I twist the cap a little, the airlock bubbles for a while. I am thinking there might be a leak around the cap. Does anyone else use a carboy cap during fermentation? Anyone have one leak on them? It probably isn't a big deal, but I am a bit concerned with it letting things in if it is letting c02 bypass the airlock.

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There are 2 sizes of carboy caps available: Regular for 5 gallon carboys and small for 6.5 gallon carboys. I have both and they seem to fit well. The 6.5 gallon one is the tightest fit. Although I suspect different bottle manufacturers make different size necks.

I had no luck in boiling them and then fitting them. Boiling just made them very soft and when cooled they went back as they were. I have one cap which is sort-of tight that I’m using on a Dunkelweizen… ferment was vicious first two days; I used a blow-off on the cap and it held. The ‘other’ cap seems too loose to use.

Where are these made?!? I love the idea, I love the extra 0.25” head space, but who’s the person responsible for quality control?!? It’s obvious that these are a hit-or-miss product. Better just to bring your whole glass carboy collection inside your LHBS and try-em-on!?! Stupid Carboy Caps!

Are these patented?!?

Zombie thread.

I use the purple ones made for a 6.5 gal. acid carboy. The 5 gallon ones are orange. At least at my LHBS. I've never had trouble with them leaking, in fact, if it's below 60F those damn things will take your fingernails off trying to remove them.

smizak said:

Zombie thread.

I use the purple ones made for a 6.5 gal. acid carboy. The 5 gallon ones are orange. At least at my LHBS. I've never had trouble with them leaking, in fact, if it's below 60F those damn things will take your fingernails off trying to remove them.

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I have several, and I thought they were great. Until I used them for wine in a 5 gallon carboy (orange cap). In less than 4 months, I had a slightly oxidized chokecherry wine in one carboy. It seemed to fit quite well, but apparently not as well as I thought!

So, I'd use them for beer and short term wines- but never again for a longer time!

Yooper said:

I have several, and I thought they were great. Until I used them for wine in a 5 gallon carboy (orange cap). In less than 4 months, I had a slightly oxidized chokecherry wine in one carboy. It seemed to fit quite well, but apparently not as well as I thought!

So, I'd use them for beer and short term wines- but never again for a longer time!

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I wouldn't either. I actually have heard Jamil Zainasheff say that he uses those caps when aging Flanders beers, they leak the perfect amount of O2 in without being too vinegary.

Some tin foil squeezed around the neck of a carboy is all you need.

IceFisherChris said:

Some tin foil squeezed around the neck of a carboy is all you need.

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The problem I have with that, especially if the beer is gonna be in the fermenter any appreciable amount of time, is eventually the CO2 pressure will equalize and air will begin to diffuse into the headspace. Oxidation sucks. With minimum a stopper or carboy cap with an airlock, they tend to hold a slight amount of positive pressure and will allow far less oxygen in.