Ripe sweet grapes
10 ml lime per 5 litre grape juice*
De-stalk the grapes, put berries in a big bowl and crush.
Cover the bowl and leave for grapes to ferment – this can take a few days.
Wait for skins to rise to the surface, pour liquid through a sieve.
Measure liquid to calculate the lime required.*
Add the lime.
Leave for 30 minutes.
Skim off the scum and strain the juice.
Heat to boiling point in a big heavy bottomed pot and strain again.
Pour back into pot and bring to a quick boil.
Skim off scum if necessary.
Test for setting point.
The texture has to be thick and syrupy.
Pour the jam into warm, dry and sterilised jars and seal immediately.