Just had my first explosion last night. Very disheartening to discover a 22oz bottle spread all over the basement floor with little tiny shards of glass splattered everywhere. I remember overfilling one of them, so I think that's the culprit and don't expect another from this batch. The milk crate I had them in was covered so the spray pattern was only in one direction, but that was by sheer luck.

Anyway, I'm now on tiptoes around my bottles since they could go off at any moment and make another large mess. I've got the crate wrapped in towels for the remaining week of conditioning, but I'm trying to come up with a way of storing the bottles that are conditioning to make it easy to clean up the mess.... What do you do? Store them all in plastic tubs?

Details about bottling this batch of Irish Red extract kit:

  • 5 gallon batch (I messed up the OG reading, the instructions said it should be ~1.044)
  • bottled after 12 days in the primary
  • gravity had stabilized at 1.015 for several days (the instructions expected FG: 1.010-1.012)
  • added 5oz of dissolved corn sugar (a Brewer's Best priming packet ) to the bottling bucket
  • racked the beer onto the priming sugar (to mix it)
  • filled the bottles: about half in 12oz bottles, half in 22oz bottles, and one flip top growler

The day it exploded we had a heat wave move in so my basement increased from 64F to 72F and the barometric pressure dropped quite a bit.

I've consumed several of the 12oz bottles and nothing seemed weird about them except they were still green. In fact, they didn't have much head, so I was actually worried about undercarbination.

The Cause:

I took @Jeff's suggestion and opened and recapped every bottle. Turns out that I had three time bombs waiting to go off that foamed all over the place. I had missed those four bottles with the bottle brush and sent them straight to the sanitizer solution, apparently without looking too closely. Those three gushers had nasty crud caked on the bottom, things floating in the beer, and they smelled bad. Based on what I've read, sounds like an infection. The rest looked fine when I held them up to the sun with a thin white film on the bottom. The bottles were from several cases of 22oz bottles I had inherited from a friend that were really cruddy since they'd been sitting with sediment in a garage for several years. I was checking them pretty closely before moving them to the sanitizer to make sure they were clean, but it looks like four of them skipped a step in that process.

Results: My compost pile got three beers and I got a good lesson in the importance of cleaning and sanitizing. And no one was hurt.

7 Answers 7


I recently had my first bottle bomb (actually 2 side-by-side) after over 10 years of brewing. The fact that they were in a cardboard box helped.

But if I were you I'd immediately:

  1. refrigerate all bottles, and
  2. carefully open and re-cap each one.

Never mind about planning for it to be easier to clean up. Imagine one of those shards of glass finding its way to your eyeball, or any other bit of flesh. And I'm with jsled ... I don't think this has anything to do with overfilling one bottle, unless you mean that you overfilled it with priming sugar.

  • Unfortunately, I don't have room in the fridge. You've got me worried so I'll open and recap them soon as I get the chance.
    – yhw42
    Commented Jun 8, 2011 at 14:21
  • 1
    it's worth pointing out that safety glasses are cheap - they have very nice ones at Home Depot.
    – Bob Cross
    Commented Jun 9, 2011 at 1:01
  • +1, I've had only one or two bottles blow in over 20 batches and they were in the first batch. Commented Jun 10, 2011 at 3:39
  • Overfilling isn't likely the problem. Less head space in the bottle simply means that there is more gas in solution. Half-filled bottles usually yield flat beer/cider and those filled to the top usually have more "bubbles". Over priming and poor sanitation seem to be what was the culprit in the few times that I had bottle bombs. I do tend to store my brew in sterilite 25 gal tubs, mainly because it makes it easier to organize and move the filled bottles. And cleanup (if needed) is easier.
    – drj
    Commented Jun 10, 2011 at 8:12

I'm having a hard time seeing how overfilling would cause a bottle bomb. Usually you're talking maybe a half-oz or an oz of difference between under- and over- filled. And over-filling wouldn't cause that much extra pressure. If you have one bottle bomb, you should expect the whole batch to be at risk.

Moreover, just waiting for the "remaining week" of conditioning won't do anything magical. If there's too much pressure in the bottle, there is. And time will only let the yeast possibly create more pressure.

What was your process? How long after brewing did you bottle? What was the gravity at that point? How much priming sugar did you use? How did you add it to the beer?

You should open another bottle and see how much carbonation there is, qualitatively.

Cooling the bottles will relieve some pressure, if you have the space to do it.

  • Thanks for your insight. I've added details to my question.
    – yhw42
    Commented Jun 8, 2011 at 14:20
  • +1 re overfilling, one of the guys in my brewclub "overfills" all of his bottles, he likes the way it carbonates better, and he's been brewing for over a decade. Commented Jun 10, 2011 at 3:37

I have used plastic tubs, and my last batch I finally had a couple bottles blow. Made clean up much easier. Switching to kegging for my next batch so hopefully bottling is a thing of the past for me. :)

  • I use the tub approach with a shower curtain for both fermentation(s) and also for bottle conditioning.
    – Pulsehead
    Commented Jun 9, 2011 at 13:34

Bottle bombs only happen when you either overprime, under-ferment or get a contaminating wild microbe that will consume the non-fermentables.

If you really think the entire batch has one of those issues (the filling thing probably isn't the issue) I'd start uncapping them and dumping them rather than wait for them to explode and clean up the mess.

If the beer is carbonated already then putting them in the fridge would be the logical step to try and keep the beer.


When I was bottling I always let the beer sit in the fermenter an extra week just to make sure all the activity was done. When bottling I was using a bottling wand and found that if I filled the bottle almost to the top the displacement caused by the wand in the bottle was just enough to leave the proper space between the cap and the beer when removed.

The only time I had bottles explode was when our AC went out for a day and the house got to around 90 degrees. My EZ-Cap bottles were popping all over the kitchen floor.


I've brewed about 10-15 batches now, all more or less unsuccessful because of varying temps resulting in infected/not completely fermented beer. Naturally bottling this mess resulted in bottle bombs nearly every time and after disposing of a couple of 24s a few weeks ago I decided to forsake glass altogether. I'm using plastic pet bottles which will allow me to easily gauge the amount of carbonation and are also much safer. I also switched from using the 1 gallon glass growlers to 1 gallon plastic jugs just in case the airlock ever got stuck and the whole thing decided to blow up in my face.


FWIW I haven't even gotten to bottling yet, but my plan is this. I have a wooden 'cube' normally used as a foot stool, open on one side. I'm going to take the cube, turn it open side up, and stack my bottles in it. The cube is about 30 inches, so I'll line the bottom with bottles, lay down some cardboard, and line with another layer of bottles. If I do have a bottle bomb, the mess should be contained in the cube, and if I simply cover it with a sheet, all the glass should be contained as well. Just my 2 cents... we'll see what actually happens when a bomb goes off in the cube..

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