To every gallon of water allow a pound of the best brown sugar,
and a jill or more of strong yeast. Mix the sugar and water
together, and boil and skim it till the scum ceases to rise. Then
pour it into a tub; and when it cools to lukewarm heat, put into
it the yeast spread on pieces of toast. Let it work two days; then
put it into an iron-hooped cask, and set it in a sunny place for
five months, leaving the bung loose, but keeping the bung-hole
covered. In five months it will be good clear vinegar, and you may
bottle it for use.
A cask that has not contained vinegar before, should have a quart
of boiling hot vinegar poured into it, shaken about frequently
till cold, and allowed to stand some hours.