Extract the juice from some very ripe sweet grapes Muscat, preferably.
If you haven't a fruit press, tie the grapes in a cloth and twist this over a bowl.
Let the grape juice rest in an earthenware or stoneware bowl for 48 hours.
Then skim off the film which will have formed on top.
This diminishes the acidity of the juice, and increases the amount of natural sugar.
Strain the juice through a cloth, and boil.
The jelly is ready when a little of the juice dropped into a saucer of cold water congeals and sets into a jelly.
Put into small pots or jars and cover after leaving the jelly to settle for 24 hours.