Almost half of my pale beers have trouble carbonating in the bottle, being almost uncarbonated after 2 weeks

I don't think I have ever had this issue with a dark ale or porter.


I've been brewing for the better part of a year now, doing a weekly small batch brew. I've been brewing a mix of pale and darker ales/ porters.

  • All of my beers use some protafloc for clarity
  • All of my beers use some Clarity Ferm (to make them gluten free)
  • All of my beers have 4 weeks in the fermenter (5L glass demijohn), even if the bubbler airlock flattens out before this
  • All of my beers spend 2 weeks carbonating in the bottle in a dark cupboard, using 1 coopers carbonation drop per bottle
  • All of my beers come in around 4-6% abv
  • I use a mix of yeasts in different beers, lately most of my pale beers use lalbrew verdant ipa
  • I live in the UK (if you're wondering about temperature)

I'd be happy to clarify any questions

  • How do you add your carbonation sugar? Which kind of sugar do you use for carbonation?
    – chthon
    Oct 5, 2021 at 19:03
  • @chthon I add one coopers carbonation drop to each bottle, a minute or two before siphoning the beer into the bottles Oct 5, 2021 at 22:01
  • My experience is that beers with roasted malts tend to carbonate more difficult, but there is actually nothing on your list that would give a lead to the real problem, especially if you treat all your beers the same.
    – chthon
    Oct 6, 2021 at 15:20
  • Are you using different caps? Are you able to 'twist' the cap on the capped bottle by hand at all? When this happens I'm typically less suspicious about recipe formulation than I am about hardware.
    – rob
    Oct 6, 2021 at 15:39
  • @rob I'm not able to twist any of the caps by hand no, nor am I using different caps for any of my beers Oct 6, 2021 at 17:54

1 Answer 1


Possible causes of uncarbonated beer after bottle conditioning:

  1. Insufficient priming sugar in the bottle, or no carbonation drop in the bottle. (I've made that mistake myself occasionally, thinking that I did put one in but didn't). If half your bottles are effected, I think we can rule that one out.

  2. Insufficient yeast left in the beer or insufficient yeast viability. Depending on how much yeast you settle out or how vigorous the yeast still is after fermentation you may run into problems with some bottles depending on the amount of dissolve oxygen in the bottle, which may vary. If this is the case, the uncarbonated beers will taste a lot more sugary-sweet than the carbonated ones.

  3. Leaky caps, which allow the pressure to escape.

  4. Low temperature. If the bottles condition at the low end of what the yeast will take, in-bottle fermentation may or may not take off.

And that's pretty much it, really. Not much else can go wrong. So it's almost certainly one of these factors.

  • Thanks for the reply frank! I tried an experiment by opening each bottle, adding a touch of yeast, and closing them back up. That appeared to solve the problem! Any idea how or why this could be the case? Oct 28, 2021 at 9:41
  • If adding yeast solved the problem, then the yeast was the cause. Either there was not enough viable yeast left in the beer when you bottled (too much flocced or crashed out) or the yeast was no longer in sufficiently good shape (lack of yeast health, too old, too long in the fermenter or too stressed by the primary fermentation) to take care of bottle conditioning. Oct 30, 2021 at 7:09

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