If you have 5–6 bottles of spoiled sour wine, pour them into a barrel and add 1 pail boiled and then chilled water, 2 lbs sugar or honey, and about 3 zolotniki tartar (vinnyj kamen). Set in a warm place without corking, covering the bung-hole with a towel. (Some people add an old swallow’s nest to the barrel.*) In 2 months the vinegar will be ready. Decant into clean large carboys or bottles and cork.