Place your washed, trimmed and cut fruit into a large bowl with the sugar, lemon juice, Cointreau and orange extract. Stir thoroughly and leave for two to three hours or overnight.
When you are ready to make your jam, sterilise your jars - Wash the jars in hot, soapy water, rinse with very hot water and then place on baking trays into a cold oven.
Turn the oven on to 140 C/275 F/Gas 1 and bring the oven to temperature. Once at temperature, leave the jars in the oven for 20 to 30 minutes, before turning off.
Leave the jars in the oven as it cools until you are ready to fill them.
Wash the lids in hot, soapy water, rinse thoroughly and then sterilise using boiling water, before leaving to drain.
Prepare to Test Jam (if not using a jam thermometer)
Ahead of time, place 2 saucers in the freezer to chill (ready to test when the jam is done).
Make the Jam
Tip the fruit mixture into a very large, heavy-bottomed saucepan and gently heat, stirring continually until the sugar has dissolved completely.
Now bring the mixture to the boil, stirring intermittently as the fruit softens, crushing against the sides of the pan to release some of the juice.
Once boiling, turn up the heat to bring to a rolling boil and allow to boil for about 8 minutes. Keep an eye on it, to make sure it doesn’t boil over.
If using a jam thermometer, you want the mixture to reach jam 'set point' (105 C/220 F). If not using a thermometer, remove the pan from the heat after about 8 minutes boiling and place a few drops of the jam on one of the cold saucers from the freezer. Place in the fridge for one minute, then push the sides of the jam blob with your finger. If it has formed a gel and wrinkles, the jam is ready.
If the jam is still liquid, place back on the heat and boil for a further 2 minutes, before re-testing. Continue this process until the jam is ready, each time using a cold saucer.
When the jam is ready, pour into the sterilised jars, and seal with the lids immediately, before allowing to cool.
* Note: nutritional information is an estimate & may vary according to portion size/ingredient variants.