I have 14 500 ml bottles of undercarbed beer, what can I do? It tastes great.... well very good anyway. Can I pour them into a bottling bucket, add more sugar, and re-bottle it?
Beware oxidation. Did you not use enough priming sugar? If that's the case, I'd get them cold, open each and dose with the proper amount of sugar to compensate and re-cap. If you used enough sugar, the seals are bad. Same remedy, just need better seals.
This batch was about 7+ gallons, I kegged half of it, and it was really, really good, got rave reviews from my beer snob buddy's, some did not believe that I made it. I would really like to be able to enjoy the rest of this batch...
I did not use enough sugar, my error was not understanding that the temperature to enter in the calculator was the highest during fermentation, I based it on the temperature, post cold crash, at time of bottling.
You might get some of the priming tabs: https://www.homebrewing.org/Prime-Tab_p_1986.html Once you figure out how much you undercarbed, just pop the caps off, drop the appropriate number of tabs in each bottle and reseal with new caps, Not nearly the chance of oxidation.
Are they carbed at all? If so, get some of the small carb tabs, open them, drop one in and cap quickly - think Mentos in a coke bottle! Otherwise, I can't think of a good solution.
^^^That's where I'd go, given that you have the option. I've tried the carb caps in partially carbed bottles and it's just too much of a mess. Even if it's super cold, you'll likely have a hard time getting a cap on and sealed. Keg it, carb it, drink it.