Buster,
barrelboy wrote:I'd open up a couple and add the extra 7gms, wait 2 weeks, if successful do them all.
Have you tried this?
Also, can you confirm that there is absolutely no carbonation in any bottles of this cider and that they are flat as tacks?
If you squeeze a bottle is it nice and firm? Are they all the same firmness?
Have you used these bottles before with no problem or is it the first time brewing in them?
How long was it in the fermenter after fermentation finished and before bottling?
Cheers,
Oliver