Blackberry jelly

1kg blackberries
1kg preserving sugar
Juice of 3 large lemons

Method

1. Place the blackberries in a colander and rinse carefully under cold running water. Tip the fruit into a large, heavy-based pan or preserving pan. Add 400ml cold water and bring to the boil. Reduce the heat, cover with a lid and simmer, very gently, for about 20 minutes, until the fruit is soft and pulpy. Add the preserving sugar and lemon juice. Heat gently, stirring frequently, until the sugar has dissolved. This will take about 4-5 minutes. Meanwhile, place 2 or 3 small plates or saucers in the fridge to chill.
2. Remove the lid from the pan, bring the mixture to the boil and cook rapidly for 8 minutes. The heat should be sufficiently high so that the mixture bubbles vigorously, but is not so near the top of the pan that it might boil over.
3. Remove the pan from the heat and test to see if the syrup will set by spooning a little onto one of the chilled plates or saucers. Cool for a few seconds, then push the syrup with your finger tip. If it wrinkles slightly on the surface, it has reached setting point. If not, boil for a further 2 minutes and then test again. Repeat this process, if necessary, until setting point is reached.
4. Position a large metal sieve over a large mixing bowl. Fill the sieve carefully with some of the blackberry mixture. Using the back of a large, metal spoon, push the pulp through the sieve into the bowl. When you have extracted as much syrup as you can, discard the seedy pulp left in the sieve. Continue this process with the remaining mixture in the pan until it has all been strained through the sieve.
5. Ladle the strained syrup into clean, sterilised preserving jars (see cook's tips). Cover the surface of the jelly with waxed discs and seal the jar lids with rubber seals. If using jam jars, seal with jam pot covers. Label and store in a cool, dark place.