blackberry and apple jam

1kg cooking apples, peeled and chopped
2 kg blackberries
3kg sugar
around 400ml water
In practice I always use less sugar than stated in the recipe as I don`t like things too sweet.

Simmer the blackberries and apples separately with a little water in each pan until soft.
Combine the fruit, add the sugar , stir until dissolved then boil rapidly until set.
Setting point depends on the temperature reached rather than the length of time cooked but keep stirring to avoid burning on the bottom and turn down a little if it looks too violent!
Setting point is when a little on a cold plate does not run away when you tip the plate but is held in check by its skin.
Allow to cool slightly then pour into jars and cover.
Should store for 1 year

If the amounts seem too big for you pan change as long as you keep the ratio 1:2:3 apples:blackberries :sugar