Strip the grapes from the stalks, prick each one lightly with a darning-needle, and pack them in preserving jars, with two tablespoonfuls of water in each jar. Stand the jars uncovered in a copper or large saucepan of cold water. Bring to the boil, and keep boiling for 20 minutes, or until the fruit looks cooked. In the meantime prepare a syrup with ¼ lb. sugar to each pint of water, boiling this for 10 minutes. Fill the jars with the syrup; have ready new india-rubber rings, put them in place, and screw down the lids of the jars tightly. Turn upside down to see that there is no leakage. Store in a cool place.