Exploding Carboy

1st time to site lots of great info. Made up my first batch of HB Sat. night. Was a kit based stout. Everything went according to plan and into a 6.5 gallon glass carboy with standard airlock closure. I was not in the mood to carry the carboy down to the basement that night so into a coat closet it went. Woke up around 2:00 am to check on my daughter and the airlock was bubbling nicely and yeast was doing well. At 3:00 am was awakened by loud explosion. Went out to find the closet door blown open and glass everywhere. The bottle had failed before the rubber bung.

My question is bad bottle? Has this happened to others most other posts I have seen the bung popped or the bottle was dropped. My carboy was in thousands of pieces and glass was in the wall. Will definitely switch to the overflow tube set up but am trying to get a better understanding of the physics of the situation, seems like friction should let go of the bung before glass failure. Am I taking my life into my hands for beer?

What temp did you pour the wort into the fermenter? Have you ever knocked it against something and thought, "I'm glad that didn't break!"? There's a really strong chance your carboy was damaged without you knowing it, and it was just waiting for some pressure to break.

Brand new just washed rinsed and sanitized, no bumps at all. Wort went into the bottle at 85 degrees.

Berkbeer said:

Brand new just washed rinsed and sanitized, no bumps at all. Wort went into the bottle at 85 degrees.

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I'd guess it was simply defective. 85 isn't hot enough to cause cracks. If this was the first use, you got a bad carboy.

I've never heard of anything like that happening. Is it possible that your airlock was clogged? The only thing I can think of is that it was fermenting and there was no way for the co2 pressure to get out- those carboys aren't designed to handle pressure.

Otherwise, I guess it's possible that you had a bad carboy, but like I said, I've never heard of it shattering like that. Even if there is a hairline crack, it would just break at that spot, not shatter.

I'd have to agree.
I just had to return one about a month ago.
I thought it looked good at the store but when I went to clean it up before it's first use, I realized there was a small air bubble in the glass... that could have been a disaster.
I doubt the quality assurance policy at the carboy manufacturer is the best.

Sounds like the beer fermenting in there must have been bomb.
(or the carboy was no good)

YooperBrew said:

I've never heard of anything like that happening.

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Same here. I've never heard of a carboy just blowing up. It certainly sounds like you had a bum bottle, though. Did you secure the airlock or stopper on the neck in any way?


TL

I strictly pushed the bung in by hand nothing holding it in place. The airlock was def. clogged I just don't understand how the bottle goes boom before the bung pops. It was loud enough to wake the whole house and blow open the door and still get large peices of glass out inot the room. Still finding shards today. I will be examining the next one for sure.

Berkbeer said:

I strictly pushed the bung in by hand nothing holding it in place. The airlock was def. clogged I just don't understand how the bottle goes boom before the bung pops. It was loud enough to wake the whole house and blow open the door and still get large peices of glass out inot the room. Still finding shards today. I will be examining the next one for sure.

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If the airlock was clogged, I guess that caused it. Those carboys aren't designed to hold pressure, and it sounds like the glass gave way. The bung isn't designed to be a pressure relief valve- that's the airlock's job. If the airlock is clogged, then the pressure has to go somewhere. This must be a rare occurrence, since this is the first time I've heard of it, but I know that fermentations can get pretty intense, and need a way for the co2 to get out.

That's really scary good thing no one was by it to get hurt. Very strange it wouldn't just pop the airlock first. What temperature was your closet at? Glass is never really cured and is inherently unstable.

This story makes me nervous about having my carboy in my closet. I cannot believe the rubber bung did not pop before the glass gave way. How full was your carboy? I have a 6.5g carboy and I always fill it to 5g when fermenting. I never have the foam build high enough to clog the airlock though, It makes me wonder if I am not doing all I can to get a strong fermentation. Do you know the OG of the beer? Did you use a starter? What aeration method did you use?

Another thing which is interesting to think about is that you say the fermenter was bubbling fine at 2am, and then by 3am it went boom. Which means that in under an hour the pressure built high enough to shatter the glass. The pressure must build very fast. Makes me wonder how much pressure would build up if you had a vessel which could handle the pressure. Thanks for sharing this info I will be more cautious and likely make sure to use a blow off hose from now on.

YooperBrew said:

If the airlock was clogged, I guess that caused it. Those carboys aren't designed to hold pressure, and it sounds like the glass gave way. The bung isn't designed to be a pressure relief valve- that's the airlock's job. If the airlock is clogged, then the pressure has to go somewhere. This must be a rare occurrence, since this is the first time I've heard of it, but I know that fermentations can get pretty intense, and need a way for the co2 to get out.

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I'm honestly surprised you haven't heard of something like that before. I've seen a few stories of this happening.

Was this a mail order? Maybe it was the UPS guy that said "I'm glad that didn't break!" when he dropped it.

Well, that sure is odd. It obviously has something to do with the buildup of pressure from CO2. Pretty amazing really!

Welcome to the Exploding Carboy Club. It's a different scenario but we'll take you.

Few more answers. The closet was approx 65 degrees, it was a 6.5 gallon carboy with a 5 gallon brew in it. Did not take an OG, I directly added dry yeast to the carboy. Air lock was def. working at the earlier check, and I will never ferment in the house again as it took me an hour and my shop vac in order to remove the five gallons of liquid from my living room. The carboy came from a LHBS I am going to talk to them about it this week and see if they have any thoughts. I can not imagine if the thing had gone off with me around it.

Thanks for the welcome to the club, it was surely an epic fail for a first time. The wife was going to take pictures but she decided to focus on moving rugs and stopping the flow of beer instead.

patrck17 said:

I cannot believe the rubber bung did not pop before the glass gave way.

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That's not surprising at all. A carbuoy is about 12" in diameter. A bung is about 1.5" in diameter. At just 2psi, the bung would only experience about 4# of pressure, while the jug top and bottom would each experience 216# (432# tension in bottle middle). At 10psi, that would be 17# and 1080# (2160# tension). Either way, combine a stuck stopper, a rapid pressure rise, and a flaw in the glass, and you have a very big bottle bomb.

good god.

can you say "better bottle" or "fermenting bucket"??



i knew ya could...

glad nobody was hurt. the mess had to be miserable..... that might just end the hobby there for me. cannot have small kids around with glass fragments forver in the carpet.

Nothing new to add here, I agree with the "bad bottle" theory. I will say this: I commend your mellow disposition towards this disaster. If it were me, I would probably have had and total meltdown.

wow that's crazy! never heard of this happening. Your first bach too? You should play the lottery.

I used to work at a wine/beer store. We never had exploding carboys but i do remember a few imploding in my hands because of weak spots, the liquid moves/and pplies pressure to the rigth spot and boooouuuufff.

Happend twice to me in about a year. All other employees, except one, had similar situations.

But i must say it only happend when moving the carboy's.

Next time smear some petroleum jelly all over the rubber stopper so that there's no friction disk, just even resistance.

Throw paper airplanes at it before you approach it, as well.

It sounds like some bad luck for your first batch. But it provides a couple of lessons:
- blow-off tubes are good insurance policies since they are much less likely to clog than an airlock during very active fermentations.
- glass carboys can be dangerous when/if they break, which is why quite a few brewers here use plastic fermenters (BetterBottles, buckets, conicals, etc.).

Also, it seams like the darker the color of the beer, the more likely it will create a mess. If you had made a nice blonde ale, you'd be golden.

Good luck with your next batch. Don't let this little bit of bad luck stop your brewing. It's a very rewarding hobby.

Wow, this is the first I have ever heard of a carboy going boom, (you sure you don't work for BB?)
If not, I have learned that anything is possible, no matter how un-likely, except me being happy, rich and being able to make awesome beer.

Bouza said:

I thought it looked good at the store but when I went to clean it up before it's first use, I realized there was a small air bubble in the glass... that could have been a disaster.

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I had a 1gal that failed at what turned out to be an air bubble.

Probably a bad carboy. I bought a brand new one the other day. I was getting ready to transfer a batch into it. I had sanitized it and was draining the rinse water out into the sink when I noticed a nice sized crack all along the bottom. This was caused, or at least originated from a manufacturing defect in the glass. I found one other problem spot in the carboy near the neck.

Needless to say, I inspected the replacement I got from LHBS before I took it home. Not saying that it won't blow up on me, but it's in better condition anyway. I think I'm gonna get a big bucket or tub to set it down in for aging.

telemarc said:

I will say this: I commend your mellow disposition towards this disaster. If it were me, I would probably have had and total meltdown.

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i'll agree and add the suggestion that you do something VERY nice for your wife in the VERY near future

Don't give up the hobby just because of one unfortunate incident. I do all of my fermenting with my carboy or bucket contained inside of a 45 gallon garbage can with the lid securely fastened down. This keeps the light out and keeps me from cleaning up messes when something goes wrong. With all of my mess contained inside of the garbage can, I can ferment in the house or the garage depending on temperatures plus I can add ice to around the fermenter to control my fermentation. Hope this helps.

I really like my glass carboys but these stories make me worried.

I've got a Better Bottle and two more on the way. Don't think I'll ever stop using my glass ones but I don't think I'll add anymore to my collection unless I get really good deals on them.

I am just glad it blew up at 3am not 2am while you were checking it. I wonder if the same thing would have happened if a cap was on it instead of a bung...the caps seem to be a bit looser then the bungs to me.

Another reason I am changing over to the betterbottles.

That is intense...sorry to hear about that. Clean up must be a pain in the ass

I'm glad I moved to fermenting with the carboy in a Rubbermaid container. I am getting twitchy about using glass though!

I think a good idea for you in the future is some fermcap foam control, that will keep the krausen out of the airlock and prevent this. I'll also add that I've never heard of this situation before, all the other times I hear about the carboy shooting the stopper out. Also if you don't already employ it try carrying the carboy in a milk crate, helps me a lot with my glass ones.

what was your OG?

Thanks all for the suggestions, I talked to the LHBS and they asked that I bring the airlock down for them, and that they have not had this situation before, their initial statement was nothing wrong with carboy, but we will see when I go down. Definitley plan on brewing inside a jug and storing in basement. Ya the wife took it really well seeing as one of our persian rugs now has a large beer stain on it. I will be brewing again this weekend one way or another.

That is unfortunate. I've had brews puke into the airlock but they've always snuffled on until I've got back to clean them up.

Went down to Oak Barrel Winecraft in Berkeley where I purchased my equipment and I must say they way surpassed my expectations. They replaced my carboy, gave me a new airlock, supplied tubing for an overflow, and replaced the stout kit that I was attempting to brew all for free. They have also started cutting the cross bars off of the bottom of their airlocks in order to minimize the chance of this happening again. All I can say is wow excellent service way beyond expectations. I shall brew again on Sat.

Wow that is awesome service! If I didn't live hundreds of miles away I'd shop there too!

Wow, you can't beat that customer service. Good luck with the second attempt.

That's superb customer service! Glad it came out the way it did in the end.