- 2 kg red-fleshed plums such as Omega
- 50ml water
- 1.8kg granulated sugar
- Wash plums, cut in half and remove stones. Put chopped plums in a preserving pan with water (the water stops the fruit sticking until it oozes juice). Set pan over a medium heat and slowly bring fruit to a bubble. Lower heat and cook at a gentle bubble for 30-40 minutes, stirring often, until fruit has broken down and liquid content has reduced by about one-third.
- Preheat oven to 50°C. Tip sugar into a large clean roasting tin and place in oven to warm. When fruit is ready, tip in sugar, and stir with a long-handled wooden spoon until dissolved. Warm a sugar thermometer in a jug of hottish water, shake dry and insert into jam. Let jam bubble away for about 10 minutes, or until it reaches 104°C – the setting point for jam; don’t stir during this process. Immediately turn off the heat and quickly skim off any bubbly scum from the top.
- Have warm sterilised jars ready either on a wooden board or double thickness of newspaper. Pour jam into jars – this is easily done using a jam jar funnel. Wipe rims of jars with a clean hot cloth, put lids on jars and leave jam to cool. When jars are cool, wipe clean with a damp cloth, then polish with a dry cloth and adhere labels.