Step 1

Stone apricots, reserve half the stones. Using nutcrackers or a hammer, crack open the reserved apricot stones.

Step 2

Remove the kernels and blanch them in boiling water for 1 minute, then drain and slip off the skins.

Step 3

Place apricot halves and kernels, strained lemon juice and 1 cup of water in a large stainless-steel or enamel preserving pan and bring slowly to the boil, stirring occasionally.

Step 4

Reduce the heat and simmer for 15 minutes, or until the fruit is soft and the water has been reduced in volume.

Step 5

Remove pan from heat, add warmed sugar and stir until it has dissolved completely.

Step 6

Return pan to heat, add the butter and stir until melted.

Step 7

Bring the jam to a full rolling boil and boil rapidly for 15 minutes, then test for a set.

Step 8

If setting point has not been reached, boil for 5 minutes more, then test again.

Step 9

Pour into clean, warm jars and cover immediately with waxed paper discs and cellophane covers.