750gmorello cherries(fresh or frozen - stoned weight)
250graspberries(fresh or frozen)
1kgjam sugar(with pectin)
Remove the stalks and stones from the cherries - you can do this with a straw, a special cherry stoner gadget, or just a knife. Roughly chop about three quarters of the cherries, and leave the remaining quarter whole.
Place a saucer or small plate in the freezer, (sounds odd, but you will need it later!).
Put the cherries, raspberries and lemon juice into a large saucepan and bring to the boil. Simmer for 8-10 minutes until the cherries are softened and the liquid has reduced slightly.
Add the jam sugar to the saucepan, and stir over a gentle heat until the sugar has completely dissolved.
Bring the jam to a rolling boil and cook for 4-5 minutes before starting to test the set. You will notice the frothy boil turn into more of a slow, glossy boil when it is almost ready.
When the jam has been boiling for 5-6 minutes and is starting to look glossy and thick, start testing the set. The easiest way to do this is with a thermometer - once it has reached 105°C it will be ready - remove from the heat immediately. Alternatively, put a blob of the jam onto the plate you chilled earlier. Leave it to cool for a second then push your finger through it. If jam floods back into the gap, it isn't ready yet - it should wrinkle slightly as you push it. Boil for a further 2-3 minutes then test again.
Leave the jam to cool in the saucepan for 10 minutes or so, then pour into sterilised jam jars, leaving the lids off until the jam is completely cool.
How do I know when my jam has reached setting point?Watch the pan carefully - when the jam is almost ready you will see the frothy boil turn into a slower boil with glossy surface, and the jam will feel thicker to stir. - The easiest way to test the setting point of jam is with a thermometer - once it has got to 105°C it will be ready - remove from the heat immediately. - Alternatively, put a plate in the freezer as you begin to cook your jam. When it is almost ready, put a blob of the jam onto the plate. Leave it to cool for a second then push your finger through it. If it floods back into the gap it isn't ready yet - it should wrinkle slightly as you push it. - There's a handy video about how to test the setting point of jam here on BBC Good Food website.How do I sterilise my jam jars?You can sterilise jars in two easy ways: - Put them through the dishwasher on the hottest cycle - jars, lids, rubber seals and all. They should still be warm when you fill them with the hot jam. Or, - Wash the jars, lids and seals in hot soapy water, then put them into the oven pre-heated to 160ºC for 15 minutes. Again, they should still be warm when filled with the hot jam.