Alright, so I've gone and over-primed a 5 gallon amber batch when bottling. Surprisingly, there is limited solid information available so I figured I would ask for feedback and then post the results hoping this proves useful for others.


  • 5 gallons of Amber ale, bottled into 12oz bottles
  • 3 weeks in primary fermenter at 65-67F, so initial fermentation certainly done (no OG/FG sorry)
  • Appx ABV 6-7%
  • Primed with 1lb of DME instead of 1.25 cups (so somewhere between 2.5-3x desired amount)
  • Minimal O2 in bottles outside of what's in headspace and whatever was in solution during primary fermentation
  • Bottle storage temperatures 66-68F

Current Status:

  • 48 hours post bottling
  • Opting to keep in bottles to prevent oxidation
  • Tonight I lifted cap edges enough to allow to offgas completely overnight with starsan and foil cover to prevent contamination
  • Currently plan to reseal tomorrow morning and fully recap in the next couple of days for final storage

So I've taken these steps to prevent bottle bombs, minimize oxidation, prevent infection, and generally allow the least amount of hassle/extra work. My dilema is that I'm having trouble finding a good chart of sugar consumption to know when to recap. Based on a couple obscure OG/FG charts plotted over days I'm seeing for ales that most sugars are consumed within the first 3-4 days. As @brewchez points out below that I originally did not consider, how does O2 affect sugar consumption rates? I would love to not have flat beer but definitely don't need bombs so does anyone know about sugar consumption rates during fermentation? Based on what I'm seeing I should be able to safely recap either on the third or fourth day and let the beer do it's thing without problem as most of the sugars have been consumed. Am I missing anything?

What I need help with:

  • Do any of you good people have solid info/knowledge about sugar consumption rates over time during beer fermentation?
  • Should I fully recap for conditioning at day 3, 4, or 5?
  • Does low O2 like there should be when bottle carbonating/conditioning slow sugar consumption?

Final Edit/Update: Two weeks post recapping with good carbonation, no bursting, and good flavor. The solution mentioned below by @brewchaz worked nicely to determine when to recap. Ended up being 3.5 days for me and has had no ill effects. Ultimately, I decided to fully uncap all bottles for 12 hours after trying the intermittent offgassing approach as I was getting very inconsistent results with amounts offgassed, and I desired all beers to be flat when recapped. Thanks for the help!

  • 2
    As an alternative, what about letting all of the priming sugar be consumed while open, and then once it is, add an appropriate amount of priming sugar to each individual bottle before sealing?
    – chytrik
    Oct 31, 2019 at 4:51
  • That is likely the safest way to go and is still an option if people end up thinking it's going to be a safety issue. Honestly, I was trying to avoid going that route to save time, minimize exposure to contaminants, and just keep things simple. Thanks! Oct 31, 2019 at 13:15
  • Hmm... You've basically divided your 5 gallons into 50 tiny individual batches, since you're leaving them all open and there is re-fermentation going on. As such, I think there's reasonably high odds that you'll have a few bottles go a little "off" from the "average", due to more or less contamination or oxidation than the others (or both). Quality will vary. Just something to not be surprised about later on. As for when to re-cap, I agree with the others, and personally I'd let them all ferment out completely, then re-prime when it seems safe. 1/2 teaspoon sugar per bottle, or equiv.
    – dmtaylor
    Nov 1, 2019 at 3:23

1 Answer 1


Too many variables to predict the rate. That's why you can't find a chart.

Temperature, ABV of beer, yeast cell count per bottle, yeast viability, residual extract in beer (related to FG), dissolved O2: All these things contribute to your specific question about rate. It is not going to be universal.

You need to sacrifice a few bottles along the way and do hydrometer readings until the gravity of the beer is close to what it should have been with the proper amount of priming sugar in it. Then re-cap. That's the most scientific way to do it. Problems though: 1. Its going to happen pretty fast you might have already missed it. 2. You need a FG specific hydrometer for the sensitivity. 3. If you don't have the FG before you primed then you really don't know how many gravity points represent the priming sugar.

  • Fine, use science and math to make this right. Now that you point out the potential hydrometer reading points your method makes perfect sense and would be the right way to handle this problem. For full disclosure, this is my second batch and I skipped taking readings because outside of messing things up the information wasn't particularly necessary. This is a strong reason to start being more scientific in my process and nail down hydrometer readings as well as understand their uses. Thanks!!! Will edit above to show what information I do and don't have. Oct 31, 2019 at 13:34
  • Yes, an hydrometer to measure starting (OG) and finishing gravity (FG) is the minimum. It doesn't take long
    – Philippe
    Oct 31, 2019 at 16:10
  • 1
    Update: I have done the reading and math to go with your method. It's pretty rough but the best I can do with my current tools. The FG was supposed to be 17 points, the correct volume of priming sugar should have added 2 points but my incorrect volume added 8. When I checked last night at ~72 hours post bottling the gravity was at 19 points which is what it should have been with the correct amount added. There is ton of room for error and rounding unfortunately. I have recapped and will monitor. Nov 1, 2019 at 17:28

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