We make a batch of this every year and it really is the easiest of jams. If your pot is big enough and you find a good supply of raspberries we suggest scaling this up: this time we used 3kg raspberries but could easily stretch to 6kg in our pot if we had enough jars free.
Before you start you need to sterilise your jars. Heat oven to 140C/120C fan/gas 1. Wash the jars in hot, soapy water, then rinse well. Place the jars on a baking sheet and put them in the oven to dry completely. Alternatively run the jars through the hot cycle in the dishwasher.
- 1kg raspberries
- 1kg jam sugar (the sort with pectin added)
- juice of 1 lemon
Put a plate in the freezer to chill.
Put half the raspberries and the lemon juice into a preserving pan. Mash the berries with a potato masher over the heat, then leave to cook for 5 minutes. Tip the cooked berries into a sieve over a bowl. When the juice has drained into the bowl start pushing the pulp through the sieve with a wooden spoon until you are left with only seeds in the sieve. Discard the seeds.
Tip the contents of the bowl back into the preserving pan and stir in the sugar. Heat gently, then add the rest of the whole raspberries. Bring to the boil and boil rapidly for 5 mins. Take off the heat and drop a little jam onto the chilled plate. Push your finger through it – it should wrinkle and look like jam. If it doesn’t, boil for 2 mins before testing again.
Stir the jam well as it cools, then pour into your sterilised jars and seal. It will keep unopened for a year, although the colour will darken a little. Keep the jars in the fridge once opened.
(Original recipe from BBC Good Food)