OK, so two months later I bottled my cider in swing-top bottles, bottle-aged it for another couple of weeks, and I just had my first glass.
It’s…meh. There is nothing about it that is actively bad, but it's definitely not *good*.
Here's the challenge with homemade cider: it can either be sweet or carbonated, but not (easily) both. And this is *neither*, which is not a great combination.
When cider is done fermenting, the yeast has turned the sugars into alcohol. So it's no longer sweet. Also, the yeast has died off (because it ran out of sugar to eat or the alcohol got so high that the yeast can't live), so there are no longer any bubbles.
You can correct that by adding sugar just before you bottle it, if you kill off the yeast, which makes it sweet but not carbonated. Or you can add a bit of sugar before bottling, which will make it carbonated but not sweet.
I added a carefully measured bit of sugar to every bottle before bottling (too much and the bottle will explode), which somehow resulted in the cider being neither sweet nor carbonated. The bottle I opened was much improved through the addition of simple syrup, although of course it wasn't sparkling.
I've added a simple syrup to the other five bottles, and I hope to drink them at the perfect point when they're carbonated but still have sweetness.
Backsweetening my cider did nothing to make it fizzy, so I added a pinch more yeast (which fizzed instantly) and waited a few days. I killed off the yeast with campden tablets, and just had some with lunch.
It’s pretty good! A little sweet, fizzy, entirely legit. I’ll enjoy drinking the rest, now that I’ve fixed them. And it all started by adding some yeast to a store-bought jug of cider.
@waldoj
IIRC there's a few solutions, some of which you may have already come across.
1. Heat pasteurize the bottles at the right point during bottle conditioning to have carbonation and some sweetness. Find the right point by putting some in plastic so you can gauge the pressure.
2. Use a sweetener that the yeast can't digest for sweet.
3. Bottle off a keg with a counter pressure filler. This is the most expensive but the easiest and least dangerous (no exploding bottles).
@waldoj @donw Probably with one of those home carbonators thingies with the CO2 cartridge. I think you're only supposed to use them to make seltzer (lest something sugary backsplash into the mechanism) but obviously it's more fun to carbonate random things.
You can also drop a pellet of dry ice into a glass of the cider and wait until it has sublimated. (*Fully* sublimated, nothing skating around on the surface.) Never in a closed container. And then you can play with the rest of the dry ice.