Whilst following my first batch of home brew instructions, rather than using a Priming Calculator we added the amount recommended for bottling (1/2 teaspoon per pint). It's been in the pressure barrel around 4 weeks and is very low on CO2, poured a pint off which had some kick from the tap and then it glugged. The ale is also fairly cloudy.

I tried adding a CO2 bulb in the top, this resulted in a good 1/2 pint then back to the above.

Given the batch has been in the pressure barrel for 4 weeks and I know I added around 15 teaspoons to the brew - what is the best way to try recover this underprime. Should I try adding more CO2 bulbs, or is it worth adding more sugar and trying to restart the secondary fermentation? I should also point out the barrel is well sealed with vaseline on all the joints.

  • "then it glugged" - what does that mean?
    – mdma
    Commented Sep 1, 2013 at 20:13
  • Air bubbles coming back up the tap and into the top of the barrel.
    – Jim
    Commented Sep 2, 2013 at 8:19

2 Answers 2


You are not likely to have much success trying to force carb in a pressure barrel as they will generally vent before reaching a high enough pressure in order to protect the pressure barrel. They are not designed to hold pressure to the degree kegs are.

After 4 weeks, unless the pressure barrel was stored too cool, you are likely to have all the carbonation you are going to from whats in there. I would suggest adding some fresh yeast as what is in there probably has very little viability now as it is probably over 6 weeks old by now allowing for primary and add some more priming sugar. Normally you would want somewhere are 80 - 100 grams of sugar depending on the level of carbonation you are looking for.

  • In the end I took the barrel out of the dark into around 25 degrees for a week. I checked the seal on the barrel and it turns out there was a slight leak on the cap. This was tightened and one bulb allowed me to get out 12 really good pints. Thanks for suggestion
    – Jim
    Commented Sep 9, 2013 at 18:32

I've not used this type of equipment, but if you're sure everything is sealed then you should still be able to add more priming sugar and re-carbonate the brew. 4 weeks is a little on the long side, so the yeast may not be as viable as they were, but there will still be sufficient yeast in the beer to carbonate, but it may take a while - a couple of weeks.

You could force carbonate with the CO2 bulbs but you might need quite a few of them, so I would only do that if in a hurry!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.