1 kilogram frozen blackberries, thawed
350 grams apples
2 cups water
juice of 1 lemon
Thinly slice the apples, leaving the core in and the skin on. Place in a saucepan with the blackberries and water. Bring to the boil, reduce the heat and simmer until the apples are very soft.
Remove the fruit with a slotted spoon and place in a food processor. Blend until smooth.
Place a sieve over a bowl and push the fruit pulp through using the back of a spatula or large metal spoon. You should only have about 1⁄2 a cup of seeds left to discard. If you have a lot more than this left in the sieve, then the sieve you are using may be too fine.
Strain the cooking liquid over the sieved pulp and whisk together. Weigh the mixture and add an equal amount of sugar. e.g. 500 grams of pulp needs 500 grams of sugar.
Place back in a clean saucepan; add the lemon juice and heat gently to dissolve the sugar. Increase the heat and boil rapidly to setting point, skimming any foam from the top as required.
Pour into warm sterilized jars and seal. Store in a cool dry place. Makes about 4 cups