Step 1
Combine the peach, raspberries and sugar in a saucepan. Juice the lemons, reserving the seeds. Place the seeds in a piece of muslin and tie with kitchen string to enclose. Add the lemon juice and seeds to the peach mixture. Set aside overnight to release the fruit juices.
Step 2
Place the peach mixture over low heat. Cook, covered, stirring occasionally, for 1 hour or until sugar dissolves and peaches are tender. Increase heat to high. Bring to the boil. Cook, uncovered, stirring occasionally, for 20-30 mins or until jam reaches setting point. (To test if jam is set, place a saucer in the freezer to chill. Remove jam from heat and place a spoonful of jam on the chilled saucer. Return saucer to the freezer for 1 min. Run your finger through the jam to test if the jam wrinkles and gels. If it doesn’t, return jam to the heat for 5 mins, then repeat the test.)
Step 3
Meanwhile, to sterilise two 375ml preserving jars, place jars and lids in a deep saucepan and cover with cold water. Place over medium heat and bring to the boil. Cover. Reduce heat to low. Boil gently for 10 mins.
Step 4
Use tongs to carefully remove sterilised jars and lids. Place upside down on a clean tea towel. Use tongs to remove and discard the lemon seeds from the jam. Carefully divide the hot jam between the warm sterilised jars and seal. Turn the jars upside-down for 2 mins. Turn upright and set aside to cool completely.