Bottled beer lacks carbonation

[kaiserben]

I made a Belgian Blond Ale and bottle conditioned it. But after 8 weeks the resulting beer lacks proper carbonation (I'm gonna estimate it's at about 2 volumes CO2. Head forms, but disappears and there are no visible bubbles after that).

Is there any way of now, after the fact, adding some carbonation to these bottles? I can muck around with CO2 and a carbonation cap if that'd work? Would like the option of putting a properly carbonated bottle in a competition.

(EDIT: have some in PET and some in glass)

 

[wide eyed and legless]

You can try adding more sugar, but have you any ideas why your carbonation is low?

 

[kaiserben]

Not really. The yeast should have been able to cope (S-33, and alcohol somewhere netween 7.5-8%).

I'm fairly sure I got my priming sugar calcs right. So I'm at a loss.

 

[wide eyed and legless]

Poor sealing? But if you have used both glass and PET that should eliminate that theory, I would just try adding more sugar what sort of temp have you kept the bottles at?

 

[Blind Dog]

You could take a hydro sample (make sure you remove as much CO2 as possible and that its at 20C) to check the sugar have been eaten. Don't base it on taste alone.

How many have you tried, how did you add the sugar to the bottles (individually,in the FV, or in a separate bottling bucket). Uneven carbonation can result from a less than even distribution of sugar and/or yeast to each bottle

Not sure I'd be adding sugar to glass bottles unless I was certain there was no danger of bottle bombs

 

[Dan Pratt]

Have you tried cleaning your glassware properly? I found that after a dishwasher cycle a thin film always ruined the head of the beer, even on headmaster glasses with nucleation's.

Try rinsing with hot water a couple of time you take them out of the dishwasher and then final rinse with cold. Leave to drip dry.

 

[kaiserben]

The batch was bulk primed in bottling bucket.

Bottles have been stored at 20-25C.

Will do a hydro sample on the next one I crack open.

Although I do wash glasses in my dishwasher I haven't had any issues with any of my other beers.

The only thing I can put it down to is maybe I got distracted on bottling day and stuffed up the priming sugar amount somehow (I've looked back at recipe data and it's fine, so maybe human error saw me use wrong amount at the time).

If I do a hydro sample and it's back to it's post-ferment FG, how would I decide how much sugar is required to get the carbonation where I want it?