When yeast have converted fruit sugars to alcohol, you are ready for Part B: Converting alcohol to vinegar. The persimmon/water-kefir culture took about 6 days to convert from a fruit mash to a "must" or young wine. I know it’s ready because it has a boozy smell, the fermentation has slowed significantly, and it tastes boozy but slightly sweet.
Part B: Converting alcohol to vinegar:
1. Press the mash to obtain the liquid. I used a sieve + cheesecloth.
2. Pour the liquid into a pot with a lid.
3. Heat liquid gently to 140℉ to stop the yeast and prevent further conversion of sugars to alcohol. Cover pot with lid and let sit for 15 minutes.
4. Allow liquid to cool room temperature. Then weigh the liquid.
5. Back-slop with raw apple cider vinegar: Calculate 20% of weight of persimmon liquid. Inoculate by adding 20% raw apple cider vinegar ( or any vinegar with the mother) to ensure that acetobacteria are present to convert alcohol to acetic acid.
6. Select a clean non-reactive/non-metal fermentation vessel. It will be large enough to allow maximum surface area. I used a 64oz mason jar, filled about 1/2 way.
7. Pour the cooled persimmon liquid and raw apple cider vinegar into the fermentation vessel. Stir.
8. Secure with cheesecloth.
9. Leave it to ferment.
10. Taste after a few days. Stop the fermentation when you are vinegar happy.
11. When vinegar is ready, bottle it and store in the refrigerator to allow flavors to further develop.