* 1kg fresh or frozen raspberries, thawed if frozen
* 100g granulated sugar, for every 100ml juice
1. Put the berries and 300ml of water in a stainless steel saucepan and bring to the boil. Reduce the heat and simmer for 10-15 minutes, or until the berries are soft. Spoon into a jelly straining bag and allow to drip overnight. Place 3 saucers in the freezer to chill – you’ll need them later to test the setting point of the jam.
2. The next day, sterilise about 4 jam jars in soapy water and rinse them in clean warm water. Allow them to drip-dry, upside down, on a rack in the oven set to 140C/Gas 1. Leave them there for at least half an hour while you make the jam.
3. Measure the juice that dripped through the jelly straining bag; then measure the sugar according to the proportions above. For 750ml juice, for example, youâ€™ll need 750g sugar. Pour the juice into a clean preserving pan and stir in the sugar.
4. Warm the mixture over a low heat until the sugar has dissolved. Increase the heat and boil rapidly for about 5 minutes. Using a metal spoon, skim off any scum from the jelly as it rises to the surface.
5. Reduce the heat and test for a set: dollop a teaspoonful of the mixture onto one of the saucers from the freezer and leave for a few seconds, then push the mixture with your finger and if it gives a little and seems to be setting, the jam is ready. When the jam has reached setting point, pour into the hot sterilised jars, seal and label.