3 large (600g) Granny Smith apples, cored, roughly chopped
Juice of 1 lemon
2 1/2 cups (550g) caster sugar, plus 1 tbs extra
4 x 250g punnets strawberries, halved
3 x 125g punnets blueberries
2 cinnamon quills
Place the apple, half the lemon juice, 1 tbs sugar and 2 1/2 cups (625ml) water in a large saucepan over medium heat. Bring to the boil, then cook for 20 minutes or until apple is very soft. Mash with a potato masher then pass through a fine sieve into a bowl. Return to the pan over low heat and cook puree, stirring occasionally, for 10 minutes or until slightly reduced and thickened. Remove from heat and set aside to cool.
Place a saucer in the freezer. Place berries in a large saucepan. Add remaining 2 1/2 cups (550g) sugar and stir to coat the fruit. Stand for 15 minutes. Add cinnamon, remaining lemon juice and apple puree, then place over medium heat and cook, stirring and skimming surface occasionally, for 45 minutes or until fruit is softened.
Reduce heat to low, attach a sugar thermometer to the side of the pan and cook jam until it reaches 104°C (this can take up to 1 1/2 hours). Remove the plate from the freezer and drop 1 tsp jam onto it. Let it set for 30 seconds then tip the plate slightly. If the jam slides down very slowly, it’s ready, if not, cook for a little longer, then test again. Cool slightly.
Discard the cinnamon, then pour the jam into sterilised jars and seal.