Halve and stone the apricots. Crack the stones and remove the kernels. Mix the fruit with their kernels in a large saucepan and pour in the water.

Bring to the boil and reduce the heat, then cook the apricots, uncovered, for 5 to 10 minutes until they are just soft.

Add the loganberries to the pan and gradually stir in the sugar. Stir the mixture over a gentle heat until the sugar has dissolved completely, bring it to the boil and boil hard until setting point is reached.

Stir in the butter to disperse the scum and transfer the jam to warmed pots. Cover with waxed discs, waxed sides down, and leave to cool completely.

Top the pots with pieces of cellophane or airtight lids and label them neatly.