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Uncarbonated Beer

What should you do when your bottled beer doesn’t carbonate?

My first rule of thumb is to WAIT. Sometimes we rush into wanting to try our beer and it hasn’t had enough time to carb up. I have had beer that carbonates in a week, but that doesn’t usually happen. (When it does it still tastes sort of green, requiring longer conditioning anyway.)

If you have given the beer three weeks to carb up at least and it’s still flat, the next factor to examine is temperature.  It’s OK to move the beer to a temperature that is higher than your normal fermentation temp.  There is so little fermentation that goes on it generally won’t hurt it much.  For me, 70-72F is a good temp to carbonate at naturally (even though I like to ferment at 65-68F).  Sometimes this step is as simple as bring the cases of beer up from the basement and into the corner of a spare room for a week or two.

If it’s still not carbonated, now what????

Well, you have to really think back now and try to remember if you added the priming sugar.  If you think you forgot to add priming sugar, then find a way to remind yourself next time to be sure you add it.  Maybe if you drape the bag of sugar over your capper so you can’t miss it….or tape the bag of sugar to your chest.

If you think you forgot the sugar you can to add a little sugar to each bottle, but weighing out suck a small amount is tough for each bottle.  Another option would be to make a concentrated solution of sugar in water and use an eye dropper to put in the required drops to be the same sugar per bottle as intended.  (Of course, this all requires a little math on your part).  Probably an easier solution would be to try CarbTabs. These are little sugar tablets that go in each bottle.

The last resort that I don’t really recommend is pouring the flat beer into the bottling bucket again and adding sugar on the whole.  Personally, I would rather dump out the beer or drink it flat.  The process of carefully collecting all the beer again will certainly oxidize the beer making it taste really bad even if it does carb up.  I’d rather chalk it all up to a learning experience than drink oxidized beer.

So if you beer is flat and doesn’t seem to want to carb up, try my suggestions.  You can always keep it and mix it with a new batch of beer that you intentionally over carb with an extra ounce of priming sugar.  Then blend the two in the glass.  I think that is the best way to rescue a batch if you can’t bring yourself to dump out a whole batch.

Good luck.  Let us know if you have more interesting methods for rescuing flat beer.


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  1. Last summer, I had a few flat batches in a row.

    My idea was to add more yeast to the bottles, since they were all big beers (over 8% ABV). This worked for some and not for others. I could never bring myself to pour them all into a bucket. I, too figured that the oxidation wouldn’t be worth it. I never thought of adding more sugar.

    I did find one more option that worked OK. I took one of the really high alcohol (11%) uncarbonated beers that was really underattenuated and mixed it with seltzer. That stuff is so fizzy and subtly flavored, it went great with the flat sweet beer. Any BMC product would also probably work in this case.

  2. Mike

    The seltzer thing is a very interesting idea. I may have to try that on some beer next time I have some left over from a bottling run.

  3. Jim Tumber

    If you used a sulfite-based glassware cleaner, the trace sulfites will kill your yeast. Once that happens, there is nothing you can do. The varialbility in rinsing methods and concentrations of the sulfiting agents could explain why there is some batch-to-batch variation in carbonation: batches using higher concentrations of sulfiting agents and shorter or cooler rinse cycles could result in lower carbonation.

    Also, to add to the comment about conditioning temperature: check the optimal fermentation range for the yeast you are brewing with. If you are using a lagering yeast, you may have to LOWER the temperature of the beer to get kick-off the conditioning.

  4. Nate

    Another option, albeit somewhat expensive, is to force carbonate in a keg. If you’re in a metro area, you can usually find a setup on craigslist. I have no idea how bad the oxidization would be from dumping the bottles into a keg. While it may be a bit slow going, it would be possible to siphon from the bottle into the keg. This way, very little beer would be exposed to air.

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