Several weeks ago I started some pear vinegar, using peels and cores that were left from the many pears I canned last fall. I froze the peels/cores in quart-size zippered bags to make juice for jelly, but decided to use some to make vinegar.
Here is a recap of the directions:
Put the fruit in a clean jar, cover with filtered (non-chlorinated) water, add sugar (1/4 cup to a one-quart jar), and cover loosely. It works best if you can add some raw vinegar such as Bragg's Vinegar. Set in a warm place, and stir daily.
If you plan to buy Bragg's Raw Apple Cider Vinegar for this purpose, look at all the bottles on the shelf and choose one that has "mother" in the bottle, or has the most sediment in the bottom. You can usually find Bragg's in your local health food store if not in your supermarket.
I used a half-gallon jar and 1/2 cup of sugar. I added some mother-of-vinegar and the rest of the plum vinegar from my last batch.
It began "working" almost immediately - it reminded me of sourdough starter. When I took the cover off daily to stir it, to my surprise it was bubbling and obviously fermenting just like it's supposed to. This is the first time I've had mother-of-vinegar to add, and what a difference it's making. A little vinegar fly discovered it too. This is why you cover it with something that will let air in, but not the little flies. A thin hankie works well. I put the hankie over the top, then screwed on the canning ring to hold it in place.
After a few weeks, the appearance of the fruit had changed dramatically. I'd stirred the jar of vinegar each day to incorporate air, just like my sketchy directions directed. It smelled very vinegary; as I'd walk past the jar on the counter I often caught a strong whiff of vinegar. The fruit had disintegrated too. It was no longer recognizable as peels and pear cores; instead it was a kind of mush. I don't know if this is the action of the working vinegar, or if it's because the fruit was frozen.
The bubbling had stopped so it was time to remove the fruit. I poured it through a strainer into another clean jar, put a clean hankie over it, and will let the flavor develop for another week or two.
You make towers of strainers and things too, don't you?
The mushy fruit went onto the compost pile. (The dogs and cats get most of the leftovers around here. If it's something they shouldn't have, it goes to the chickens. If the chickens can't have it, I bury it in the compost pile so the dogs and cats can't get to it.)
After a couple of days the solids have settled to the bottom. There is about an inch of sediment in the bottom of the half-gallon size jar, fruit mush that went through the holes in the stainer. In a couple of weeks I'll pour the finished vinegar into a pretty bottle and strain it through a cloth to get a clear liquid.