OK…I left my cider in the secondary for 21 days and put 3/4 can of frozen apple juice concentrate in the gallon jug with 6 packets of stevia. I then put it in EZ Cap bottles with about 1 inch of space at the top of the bottle.
I was planning on leaving the bottles out for 5 days then testing. Leaving longer if the desired fizz wasn’t achieved.
Once achieved I was going to pop them in the fridge to stop the yeast from dancing.
Am I risking bottle bombs and if so… What do you recommend?
At this point, you may want to consider leaving them @ room temp and trying one every 2-3 days (this shouldn’t be a terribly tall order for any homebrewer!). Check the carb level, and once you get it where you want, store them cold…for several months (if they last that long).
More experienced cidermakers will hopefully chime in, but when backsweetening as you did, it is tough to know how much CO2 is going to be created.
Whatever you, do not risk bottle bombs. They are literally just that. Glass claymore mines that will go off randomly in your house and injure anything around them.
The standard can of apple juice concentrate is 12 fl oz, and tells you to mix with 3 more cans of water, which results in 48 fl oz apple juice.
One serving is 8 fl oz, so 48 fl oz is 6 servings.
27 grams sugar in one serving is approximately 1 oz sugar.
So, 1 can concentrate contains approximately 6 oz sugar.
You used 3/4 can, so you have used approximately 4.5 oz sugar.
If you used that much sugar to prime 1 gallon of finished cider, you used about 5 times too much. Hence you have made bombs. You really ought to open all the bottles and let them ferment back down to completion and/or start over. Although…
The stevia will likely make the cider taste nasty anyway.
As another option, you and your friends could try to guzzle all the cider within the next 48-72 hours before they start to explode. If you want to try carbonating these, you should check a bottle every day to be on the safe side. But I do think there is some danger involved. Once they are carbonated, refrigeration will not prevent them from exploding.
Sorry to sound all gloom and doom, but I’m pretty positive that you overprimed, and not just a little but severely.
He could heat pasteurize. Cold may or may not work. Everytime I have tried to save a beer or cider from overcarbonation by refrigeration, I ended up with gushers or bombs anyway. The yeast still works in the 30s, just more slowly. But if you feed them 5 times as much priming sugar as normal… I think they’re going to feast, even in the 30s, to potentially dangerous levels.