Jam is one of the simplest... a basic ratio... just 1:1 Using blackberries and a crack of black pepper to slightly spice this one makes it extra special.
Weigh an equal weight of blackberries and caster sugar into a large saucepan and squeeze over a bit of lemon juice. Crack in the black pepper and heat to a boil, then simmer for 10 minutes.
Check the jam is at the right setting consistency by testing a blob on a cold/frozen plate. It'll cool quickly and you can see how thick it is. Cool completely before storing in a clean jar for use.