I purchased a 12 pack of swing-top bottles at a decent price. I only now noticed that over time as I drank through the batch, the bottles were less and less carbonated, ranging from perfect carbonation in the early bottles to virtually no carbonation in the later bottles. I've never had an issue with losing carbonation in previous batches in capped bottles, so I can rule out my technique for carbonating. In hindsight I'm starting to think the bottles were a great price because, well, they're cheap bottles.

I'd like to avoid buying a more expensive set of bottles (and risking the same results). Is there anything I can do to strengthen the seal of the gaskets or upgrade the seals with a better option for my next batch?

  • 1
    Are the seals old and / or crumbly? You could try replacing them.
    – Robert
    Commented Jun 27, 2018 at 20:48
  • Bottles and seals were purchased new. I might try replacing them anyway. Commented Jun 28, 2018 at 13:07
  • Were these bottles specifically "beer bottles" (eg brown glass 500ml) or were they "general" flip top bottles (eg like used for oil or other non pressurised contents). I have found that clear glass 750 or 1000ml bottles are next to useless for keeping beer in. Perfect for olive oil though.... Commented Jun 29, 2018 at 10:15
  • Seriously just use normal capped bottles. Caps are dirt cheap and a capper is a pretty small one off cost. Commented Jan 22, 2019 at 23:54

3 Answers 3


Replace the seals. Buying 100 seals from eBay should cost you something like US$10.

I also use swing-top bottles, and my protocol is to replace a seal immediately after opening a bottle that turned out to be undercarbed.

  • Also. A shot of food grade silicone keeps them fresh, and always store them unsealed. Just leave them loose covering the bottle opening. Commented Jun 28, 2018 at 19:20
  • Additionally, make sure the plug is seated properly. Something I have noticed is that the plug can seat not quite perfectly in the bottle top. I am willing to bet that cause the seal to be less than perfect, especially for pressurized contents.
    – Escoce
    Commented Oct 16, 2019 at 15:01

Even though I liked the idea of swing-top bottles, I have found that they don't seem as effective and my friend's crown sealers.

But having invested in swing tops, here are ways I've found to help with carbonation:

  • Replace the seals - specifically with the full covers, not the o-ring seals.
  • Don't over fill bottles - leave a good thumb's length of air gap - gas compresses better with more gas space.
  • Store full bottles inverted or lay weights on top of them (e.g. books)- the extra weight helps seal a bit tighter through the combination of weight and liquid around the inside of the seal (if you invert, you'll also know which bottles have serious seal issues by seeing the presence of beer/bubbles on the outside of the bottle).
  • Carbonate slightly more - I carbonate with table sugar so give each 750ml bottle about 2-4 grams extra. The good news about swing tops is the glass is often thicker and the bottles can take quite a bit more pressure.
  • Store empties unsealed - helps relax both the swing top mechanism and seal for more effective use later.
  • 2
    Storing bottles upside down gives you sediment on the neck, I don't think it's worth it.
    – effeffe
    Commented Jul 18, 2019 at 20:17
  • That is true. However, when I refrigerate them, I put them the right way up and that does an okay job of settling most of the sediment to the bottom. The small amount of sediment I have had on the swing top and rim of the bottle is easily wiped off before pouring. Commented Jul 22, 2019 at 4:57
  • This is good advice, except for the inversion. Don't do this. Creates unsightly and messy sediment at the top of your bottle and puts extra exposure of the seals to the pressurized beer instead of just the gas. Commented May 10, 2021 at 18:06
  • Unsightly/messy is hardly a concern when most of it settles when placed right way up again. Ironically, you mention exposure of the seal to beer as a negative thing, but its overwhelmingly positive: apart from the added weight of the bottle, it is harder for a gas to escape through liquid and rubber exposed to liquid lasts longer (exposed less to light, oxygen and heat - the main reasons rubber degrades). Beer is not corrosive to rubber. Commented May 12, 2021 at 3:10

I agree that replacing the seals is good because they compress with time, but only after using them for some time. I usually flip the seal once, before changing it.

Another thing you can do to get a better seal is to verify the wire mechanism. I use a pair of plyers and bend the wire a little to tighten the seal.

  • Good point. I just bent a wire on one of my recent bottles. I then set it apart from other bottles just in case it carbonated differently. Fortunately it worked and carbonated perfectly and consistent with all other bottles.
    – dmtaylor
    Commented Oct 18, 2019 at 13:10
  • Indeed, some bottles have a looser mechanism.
    – Philippe
    Commented Oct 18, 2019 at 17:09
  • Similar information here: homebrew.stackexchange.com/questions/23867/…
    – Philippe
    Commented Oct 18, 2019 at 20:15

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