Luckily for me, there was plenty of veggie-fruit sugar, and I dumped it in a bin with some artesian well water, snapped on the lid, and walked away for a while. When fermentation slowed down, I strained everything through cheesecloth, put the liquid in the big jar (above), stashed it in a cupboard I rarely open, and walked away for a while.
This is the bacterial mat that made the vinegar. The small light patches are the newborn colonies of mold, I think. The vinegar is ready, and it's time to pull off the mother floccor, strain, and bottle the product before the mold messes it up.
So, it looks like I can continue to wring another product from leftovers of juicing and cider-making. Someone asked where I got the "mother" (the colony of flocculants some people call a SCOBY, used like a sourdough starter to get the ball rolling), but so far I haven't used one. I decided to try an approach that is lazy (or smart), cheap (or frugal), and unambitious (or stoic, maybe zen), and walked away for a while. Unlike beer, where a wild ferment will not yield what beer drinkers want, vinegar makes itself with the microbes ranging free in the Eastside Olympia air.