Boil washed redcurrants with 500ml water and a mint sprig in a preserving pan.
Stir and press the redcurrants to break down the fruit.
Pour juice through a jelly bag into a bowl and leave to drip overnight.
Transfer collected juice to a preserving pan with sugar and lemon juice.
Chill a plate in the freezer for testing setting point.
Cook over gentle heat until the sugar has dissolved.
Boil rapidly for 10-15 minutes until setting point is reached on the cold plate.
Remove from heat and stir in the chopped mint leaves.
Cool slightly and pour into sterilised jars.
Seal the jars with lids and label them.