Damask Rose and Black Muscatel Grape Jelly

• 1 or 2 large cooking apples
• 1 litre/2 pints red grape juice

Wash and chop the apples and put them – including both the skin and the cores – in a saucepan and add enough water to cover them by an inch or so. Cook until the apple is almost soft, then add the stemmed grapes and cook until they too are soft. Mash the fruit to extract as much juice and pectin as possible and strain through a jelly bag for several hours or overnight.

Measure the liqui