I'm using 16oz amber e-z cap bottles (swing tops). I've read that they'll self-vent before exploding, but I've heard other accounts of them actually exploding.

I'm storing them like this and it's been a week since bottling. I've been meaning to vent them a few days ago but forgot and tonight when I went to vent them I barely touched the swing top mechanism and it blew off (very loud, like warm champagne) and started gushing.

I pressed the top back on and took it to the sink and after letting it settle for a few seconds was able to get the cap to stay shut. That one is in the back of the fridge currently. The rest are still in the cooler, and I've placed a few large ice chunks and brought the temperature down to ~50 degrees F so hopefully fermentation will slow down (if it's still going) and/or more CO2 will dissolve into the liquid until I can figure out what to do next.

My concern is exploding bottles... and the pressure is potentially still increasing every second (though unlikely after a week I would assume).

What about venting the bottles? Would the safest way be under water in a bucket to slow down the glass if it does explode? Or should I just not be so worried and move them to the fridge ASAP and just be mindful while opening them later?

How likely are these to just blow up in my hand while moving to the fridge or afterwards while opening? Is it normal for a swing top to just blow off like that at room temperature?

Any tips or advice?

Much thanks in advance...

3 Answers 3


These are very thick bottles. While I wouldn't let them pressurize forever, if you keep them cold, wear leather work gloves, and bring them outside in a bucket of ice water, you should be able to open them safely (and messily). I also recommend using safety glasses.

For safety (and cleanliness) reasons, I wouldn't try to save them. You might be ok if you can vent them without any gushing, but this depends on the reason for gushing. Were they infected or did you add too much sugar? More information is needed to tell you to save the beer, so my answer is to stay safe and get rid of the beer.

It's not possible to say how likely these are to explode or swing open on you during movement. I'd say unlikely at this time. If they do blow, chances are good they'll either just open or break where the metal top attaches to the glass (this will be a weak point). Again, wear gloves and put them in an ice bath to open/vent.

  • We're talking maybe a tablespoonish of extra honey in a gallon batch.... I actually had .78ish gallons and then used ~2 to 2.5 tablespoons of honey. The recipe called for 1 gallon and 3 tablespoons, so hopefully I just over primed a bit. Next time I'll be using a scale instead of tablespoon, especially considering the viscosity of honey, it's not very accurate to measure by volume that way.
    – Gordo
    May 22, 2013 at 21:34
  • I tasted the gusher from last night and it's fine, albeit a bit "green" sort of sour like a granny smith apple. Otherwise very tasty... I think they need a bit more time to condition so the yeast can work over the esters, but I definitely need to vent them first. I added more ice and some water just now, going to bring the temps down as low as I can and will wrap in a towel and vent them.
    – Gordo
    May 22, 2013 at 21:34
  • Huzzah! Just vented them, no problems... no gushing either. :D Gonna let them have another week, will check on them again tomorrow.
    – Gordo
    May 22, 2013 at 22:01
  • 1
    You were only 6% over what the original called for (if you added 2.5 T to .78 gal). The problem is that, according to northernbrewer.com/priming-sugar-calculator and convert-to.com/246/honey-amounts-converter.html 1T honey (21g) in 1 gal = 2.1 volumes. You were aiming for about 4.4 volumes (63g). That's about 3 times as much honey as you should use and about 2x the safe amount for standard bottles. Definite bottle bomb potential there.
    – Tarah
    May 23, 2013 at 13:28
  • Interesting... Either their instructions are really dangerous or that calculator is wrong.
    – Gordo
    May 23, 2013 at 23:46

As Thomas answered, safety is paramount right now. Glass shrapnel is a serious reality, and you don't want that in your eyes, hands, face, anywhere. Wear gloves, wear glasses, I'd even recommend a jacket/sweater when venting to keep shrapnel out of your arms/torso. Keep your beer as cold as possible to slow down fermentation.

Store them away from anything that could be damaged by them exploding. Your cooler that you have them in is probably ideal, as a bomb at most will just cover the rest of the bottles in beer. While they are thick bottles, there's no telling how much pressure they are under, so move them outside in the cooler, don't carry them out individually.

Depending on whether the beer is infected, it may even be salvageable. As Thomas said, get them chilled down before venting. The weak point is the cap. Whenever you go to handle them, wear thick gloves and hold them by the top to cut down on potential shrapnel spread. When going to vent them, cover the bottle cap with one hand to prevent shrapnel from shooting everywhere, while using your other gloved hand to pop the swing top. If it's going to explode, this is most likely the time it will happen.

If the beer isn't infected, keep a few sanitized bottles, and a sanitized funnel readily available, as you may be able to salvage the beer with a bit of oxidation as the cost. When they're that carbonated, they should keep in bottles. If they're infected, toss them.


If you want to stop carbonation, you can pasteurize the bottles. To do this, use a pot of 170 degree water and immerse bottles. Let temp get to 170 again, and let sit for 15 minutes. Not sure how this will impact the taste of the beer, but I've done this for cider.

  • 3
    I would be extremely careful here. As you heat the bottles, the pressure inside the bottles will increase and potentially blow them up if they were close already.
    – fire.eagle
    Jun 12, 2013 at 19:06
  • 3
    The issue would be twofold. As you heat the bottles, you'll naturally expand the gas in the headspace, but CO2 is also less soluble in beer at higher temperatures. CO2 will come out of solution, resulting in even more gas and pressure in the headspace.
    – jsmith
    Jun 12, 2013 at 20:04

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