Sterilise the jam jars and the rubber rings. Wet the jars wet so that the gages will slide down inside them easily.
Clean the fruit and remove any stalks. Cut the fruit in half and remove the stones.
In a pan bring the water and sugar to the boil together and then leave to cool to form a syrup.
Carefully pack the fruit into the jars and pour over the syrup to cover. Finally add the lemon slices and seal the jars.
You now need to use a pan that is deep enough to allow the bottles to be covered completely. Place a folded tea towel in the bottom of the pan so that the glass is not in direct contact with the metal. Put the jars in the pan and cover with cold water and lay a sugar or cooking thermometer on top of the jars.
Gently heat the water so that it takes 1½ hours to reach 90°C. Once the temperature is at 90°C, turn the heat down and maintain this temperature for 15 minutes exactly.
Lift the jars out carefully using gloves or tongs and place either on a wooden chopping board or cloth, never on a metal or cold surface or the sudden change in temperature will make the glass crack. Leave to cool and then store in a cool, dark place; where they will keep indefinitely.
