I made a beer over a month ago. Rather than taking 3-5 days to ferment, it took over 20. After fermentation finished, I took a gravity reading and it fell from 1.040(ish) to 1.010(ish)... Primed, bottled, and gave it a good 2 weeks to carbonate. Opened the first one, and the hiss was much shorter and when I poured it, it was almost uncarbonated.

I don't understand this, because the smack-pack was fully swollen when I pitched it.

Could I have aerated poorly or not at all?

  • How did you aerate? Commented Jun 1, 2010 at 13:34
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    This isn't an aeration problem. If you hit .010, you were probably at terminal gravity. Your poor carbonation is either because you didn't stir in the priming sugar well, or sometimes I have seen slow/poor carbonation when the environment is too chill and slows yeast activity. What you are asking is really two separate problems. A perceived long fermentation and poor carbonation. Most beers take around 7 days to reach terminal gravity. Depending on the ABV target of the beer, 10 isn't that unreasonable.
    – TinCoyote
    Commented Jun 1, 2010 at 14:23
  • @Dean, I am pretty sure I sloshed it as much as I typically do, but in thinking about what went wrong, that was the first thing that came to mind (albeit almost more than a month after the fact). @Tin, sorry. Typo. Fixed now. Are you saying that it was slow yeast? If swelling the smack-pack was any indication, it puffed the package in less than 2 hours (usually takes at least 3).
    – Pulsehead
    Commented Jun 1, 2010 at 15:16
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    Concerning your long fermentation, did you use a Wyeast Activator or Propagator? One reason I could think for that long a fermentation is that you used a propagator for a 5-gallon batch. If so, the yeast needed more time to populate and metabolise the sugars because its original population was pretty low for the batch. Concerning your not-carbonation, either you have used too little priming sugar or the fermentation process isn't complete for some reason. Commented Jun 1, 2010 at 16:54
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    What temp did you pitch at? Too high and the yeast won't be happy for a couple days.
    – brewchez
    Commented Jun 2, 2010 at 1:12

1 Answer 1


I would think, that the slow fermentation could be explained by bad aeration. The yeast will use the oxygen in a well-aerated wort to reproduce and a higher number of cells will ferment a lot more dynamically. I have had fermentations creeping along very slowly until I aerated once more and suddenly it worked just fine. Also, I have found that even the the activator-packs actually benefit from preparing a starter with them. I agree, that the lack of carbonation must have a different reason.

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