Put into a cask a mixture composed of five gallons of water, two
gallons of whiskey, and a quart of strong yeast, stirring in two
pounds of powdered charcoal. Place it where it will ferment
properly, leaving the bung loose till the fermentation is over,
but covering the hole slightly to keep out the dust and insects.
At the end of four months draw it off, and you will have a fine
vinegar, as clear and colourless as water.