I brewed a trippel, added priming sugar, and bottled it, but my bottle capper broke after only a few bottles. I placed caps atop the remaining bottles but won’t be able to seal them until I can replace the capper. These bottles will have set like this for four days. What can I do to make sure this batch carbonates? If I add a bit more primer, how much is enough? Thanks for any help!
To carbonate to a desired level, you are adding a known amount of priming sugar to beer that has a known amount of fermentable sugars (i.e., fermentation has completed, so no fermentable sugars).
After four days, you will not know how much of the initial priming sugar remains. You really are going to need to wait until all of that priming sugar has been fermented and the resulting carbon dioxide has dissipated. Then, re-prime and cap.
The re-priming will (probably) involve dumping all of these beers back into your bucket. The amount of priming sugar to add should be reduced based on the fraction of the batch that didn't get capped previously.
Given that you are going to be re-bucketing anyway, you might want to sterilize your fermenter and just let the first priming sugar ferment away there, then bottle as usual.