Updated: Oct 18, 2020
Blackcurrants are a very tart berry and naturally high in pectin making them an ideal berry for jam making.
Blackcurrants are also high in vitamin C and anthocyanins. Anthocyanin is an antioxidant found in red, blue and purple berries as well as red cabbage and the skin of aubergines. Now when you add a lot of sugar to fruits to make jam, it could be said to counter act the nutritional benefits of the fruit.
In order to maximise the yield of your berry plants, as berries are ready; pick, wash, dry and freeze them.
700g Caster Sugar
Juice of 1 Lemon
Wash the fruit.
If using small plate method to check set of the jam, put side plates in the freezer.
Add all ingredients into a large jam pot and begin cooking on high heat, stir constantly at the start to prevent the sugar burning. Once sugar is dissolved, stir every few minutes to avoid the jam from sticking.
While that is cooking, sterilise your jars and lids by washing with hot and soapy water and dry. Put the jars in an oven proof tray with an inch of water at 160°C and put the lids in a pot covered with water ready to boil when the jam is ready.
Once blackcurrants have come to the boil, turn down to a medium heat and use a ladle to remove scum. The scum is the pale coagulated top on top of the jam.
Once the jam is ready, boil the lids. The jam needs to reach a temperature of 105°C. Alternatively, put a teaspoon of jelly on a frozen small plate and when the jelly holds it's shape & does not run on the plate, it is ready.
Fill the jam jars, and seal with the sterilised lids. This will keep for at least a year.