When I bottled my last cider, I wanted it to be dry and sweet. It finished out at about 1.000 using D47. It was extremely clear (at least to me), and had finished according to my hydrometer (a span of two weeks with no drop). I opened a bottle a few days ago to check on it, and I was met with a pop! Before I bottled, I hit it with the appropriate dose of campden and sorbate; that combined with the clearity led me to believe the yeast were history, guess not. When I bottled, I sweetened it with a can of apple juice concentrate, in a volume of about 6.25 gallons of cider. If my math is right, I added an additional 7.8 oz of sugar from the concentrate.
Using some online calculators, this gives me a carbonation of about 3.25 Volumes (at 60F). I used standard, no bung, 750 ml clear wine bottles, and now I'm getting sort of nervous. It was def. fizzy (and delicious), but nothing seemed to make me question the integrity of the bottle. I didn't take an OG reading, but I will tonight when I break open another. There is a fine layer of what I am guessing is yeast on the bottom (side, whatever) of the bottle, just fyi.
Does anyone have experience with this level of carb in a wine bottle? If not I guess I'll be the first. It's setting in my racks at a temp of about 68 F. I'll keep everyone updated if anything adverse happens. If it goes to complete consumption without a single bomb, can we consider that carb amount safe?