Why is my brew undercarbonated?

Tarindel · 08-16-2008, 01:35 AM

Hey everyone. Newbie brewer here. I just finished making my second batch of beer, and it's come out undercarbonated. I opened my first bottle, and got a small hiss (about half of how much a commercial beer hisses), and there's some carbonation. The beer went flat pretty quickly.

I'm not sure what I'm doing wrong, because my first batch had the same problem.

This batch was made from a B3 Nut Ale kit. Here was my procedure for this batch:
1) Beforehand, made a small wort as a yeast starter, and poured my yeast (White Labs European Ale Liquid Yeast) into it to propagate the yeast. Technically not necessary, but I wanted to learn how to do it.
2) Brewed the wort.
3) Put the wort and the yeast into the primary fermenter (6G class carboy) and made sure they were mixed up well. The liquid yeast took off pretty fast and the airlock was bubbling like crazy.
4) Left in primary fermenter for 3 weeks in a dark closet.

5) Put 4oz of corn sugar that came with kit in boiling water, boiled for 10 mins, and cooled. Put solution in the bottom of the bottling bucket
6) Siphoned flat beer out of primary fermenter into bottling bucket (down to the trub).
7) Used sanitized brewing spoon to gently mix beer/sugar in bottling bucket to ensure good mixture
8) Bottled using a spring-loaded bottling device and capped bottles using bench capper
9) Left bottles alone in dark closet for a week
10) Took bottles out of closet and rolled them to ensure yeast wasn't settling on bottom
11) Returned to closet for another 2 weeks

So that's 3 weeks in primary fermenter, 3 weeks total bottle conditioning. The beer tastes GREAT, it's just undercarbonated.

Does anybody have any theories on why my batches of beer are coming out undercarbonated? This one isn't as bad as the last one, but it still less than where it should be.

As a side note, I carefully poured my first beer into a glass, leaving about 1 inch in the bottle. I poured the last inch into a short glass, and can not see any yeast in there. Should I be able to?

Any and all help appreciated!

Thanks in advance.

Alex

BrianP · 08-16-2008, 02:41 AM

A couple suggestions:

#10 - rolling the bottles around to rouse the yeast: this generally isn't necessary.

#5 - 4 ounces of dextrose (probably came pre-measured with your kit): you can dial in your carbonation level using some brewing software or on-line carbonation calculators. Some people always use the same amount (3/4 cup, etc.) but you can get more or less carbonation to match your beer style by adjusting the amount of sugar -- just don't go crazy with it or you'll over-carbonate and have potential for bottle bombs. Also, it's best to weigh the sugar rather than dry measure.

Lastly: temperature. If the brew was below room temp (70-72) or sitting on a concrete floor, it will affect carbonation.

Another possibility (although not likely) is that you didn't get a good seal while capping. I've also heard of people who forgot to add the bottling sugar because they had a few too many before they started the bottling process.

For now, I'd try waiting a little (the beer can only improve) and maybe move it to someplace a little warmer.

**Nurmey** · 08-16-2008, 04:35 AM

I've had a couple stubborn batches that took 5 or 6 weeks to carb. I usually use 5 ounces of priming sugar but for whatever reason, these took longer to carb. Rolling the bottles around helped a lot.