Easy Grape Jelly
Halve the grapes and cover with the water in a saucepan. Heat the mixture slowly, then pass through a food mill. Measure the grape juice, then mix with the lemon juice and jam sugar. Bring to a boil, stirring constantly. Cook for 3 minutes, until the jelly begins to thicken.
If necessary you can add some citric acid if the jelly isn't thickening properly. If using the citric acid, make sure to return to a boil to activate the thickener. Fill the prepared, sterilized jar to the brim with the hot jelly. Seal tightly and turn upside down to cool for 10-15 minutes. Turn right side up and cool completely.