Wash 1 kg blackcurrants and remove them from the stems. Place into a preserving pan or very large saucepan. Add 750ml water, bring to a simmer and cook for about 10 minutes until the blackcurrants are soft.
Add 1½ kg sugar and cook over a low heat stirring until the sugar has dissolved.
Bring to a rolling boil and boil for 10 minutes, then test for a set. Continue to boil for another 2 minutes before retesting and repeat if necessary until setting point is reached. If you have a thermometer the mixture should reach 105℃/220°F.
Pour into hot sterilised jars and cover. Label when cool.
Notes
Nutrition information is calculated based on this jam making 4 x 450g (1lb) jars and each serving being 25g (1oz)Cook's Tips
Place a couple of sauces into the fridge before starting, ready for testing the jam for setting point or use a thermometer.
StoreThe jam will keep for about 1 year after which the flavour may deteriorate. Store in a cool dark place.Once open store in the refrigerator and use within 2 months