Last 2 brews very under-carbonated...

[Flic]

I've done about 14 all-grain beers over the past year and never had any bottle carbonation issues. I use Beersmith and always calculate out the weight of corn sugar to add according to my final bottling volume. I brewed a Russian Imperial Stout a couple months ago and when I tried it, it was very under-carbed. There was only a slight hiss when I opened the bottled and there was no head at all after a vigorous pour. I only had 3.25 gallons in bottling bucket and used 2.5oz of corn sugar. I thought at first it might be the high abv and I should have used more sugar. But...my last brew was an IPA and I had the exact same thing happen!! That has only been bottled for about 20 days but they always seem to be at least be carbed at that point. I used 3.5oz corn sugar for 4 gallons on that one. These are consistent amounts of corn sugar I have used on prior beers (usually shoot for 2.4 vols) so I am confused as to why this might be happening. Bottles are stored at mid-high 70's.

 

[oojuxeoo]

I am having a similar issue with a bitter. 5 gal batch, bottled about a week ago. Wanted to check the progress, opened one up and barely a hiss, and no bubbles in the pour. Bottles stored at 69 F.

 

[kunstler]

first thing that came to mind was how the cap is seated on the bottle.

I had a similar issue - I was using some bottles someone gave me and no matter what I tried with those I couldn't get it to really carb - here I wasn't getting that tight a seal and the co2 was slowly leaking out without me really knowing it. I finally went and did a batch half grosch swing top type and half these used bottles - used bottles nothing very much swing tops perfect.

That would be the first thing I would check. if you are using grosch swing top types also check your rubber gaskets.

 

[JuanKenobi]

I have a similar situation with a dry stout. I think the problem is most likely just time. It's been bottled for almost 5 weeks now and is still barely carbed. A bad seal could be the problem, but what are the chances that every bottle got a bad seal? They are the same bottles and same caps used for other batches that carbed up fine.

In my case, I think it's probably time spent in carboy + yeast strain. The stout spent 6 weeks in primary on S-04. I'm guessing that I have fewer than average cells that are highly flocculant and it's going to take them a while to get the job done.

 

[khiddy]

To the OP: With big beers like a RIS, you need to give it more time before you pass judgment on the carbonation. The yeast are pretty tired after working through all of that wort, and it just takes more time for them to carb it up. Try again in two weeks. And then two weeks after that.

Patience, brewer-san.

 

[TheFlatline]

Also, did you let it age for a particularly long time? Did you cold crash? If you did either of those, it's possible that you did *too* good of a job getting the yeast out and they never manage to get a move on.

One option is to take a dry yeast and add a few grains per bottle to give it a kickstart. Though I agree with the above poster, give it a few more weeks.

 

[Flic]

Also, did you let it age for a particularly long time? Did you cold crash? If you did either of those, it's possible that you did *too* good of a job getting the yeast out and they never manage to get a move on.

One option is to take a dry yeast and add a few grains per bottle to give it a kickstart. Though I agree with the above poster, give it a few more weeks.

No cold crashing. The RIS was a total of a month for primary/secondary, 3 weeks for the IPA. I am going to let these go a bit longer, especially the IPA since that had only been 2 weeks. The RIS has been bottled for 5 weeks. I'm used to having nicely carbed beers at 2 weeks but the RIS is 9% and the IPA is 7.7% so I'll try to be patient. It's also getting me more interested in kegging instead of bottling...

 

[bguzz]

I've had the same issues with the last couple brews I did. I have been cold crashing for 3 days after sitting for 3 or 4 weeks in the fermenter. After 4 weeks in the bottle at about 75F, I have low carbonation. I used 3 oz of corn sugar for 4 gallons. I think from now on I will add a little us05 to my bottling bucket. I have found that it also speeds the bottle conditioning since the yeast is fresh and stronger.

 

[Lcasanova]

I was listening to and old Basic Brewing Radio podcast this afternoon. A listener wrote in that his beers were wayyy undercarbed. He put a condom over a bottle and let it sit for a while, the condom inflated meaning that the cap wasn't completely sealed around the bottle. I'd try it with a balloon but hey, to each his own! Anyways, if they inflate you might have a problem with your capper!