Remove ripe Concord grapes from the stems, wash them in a colander,
bring them just to the boiling point over a moderate fire, stirring them
frequently. Put them into a cooker for five hours or more. Drain them in
a jelly bag for at least eight hours. Each quart of loose grapes should
yield about one pint of juice. Add one cup of sugar to every quart of
juice; bring it just to the boiling point and pour it at once into
sterilized bottles, not filling the bottles quite full. Cork them at
once. When cold, press the corks down more firmly, cut them off level
with the top of the bottle, and dip the inverted bottles, for an
instant, into Wax for Sealing. If bubbles appear in the wax around or
over the cork, break them and dip the bottle again.