Place a couple of saucers or plates in the fridge ready to test your jam later.
Add chopped peaches and lemon juice to the slow cooker pot and stir.
Add jam sugar and stir. Pop on the lid and cook on low for one hour.
Remove lid and stir. (Don’t worry, the sugar is unlikely to have fully dissolved yet)
Scrape down any sugar and replace the lid and cook on low for another hour. Stir your jam mixture and turn up your slow cooker to high – the sugar will have fully dissolved by now.
Replace the slow cooker lid but this time prop it open a little with a wooden spoon to allow the steam to escape.
Cook on high for 2 to 3 hours until set.
Check after 2 hours: drop a small amount of jam on to your chilled saucer. Allow to cool for a couple of minutes and then push gently with your finger tip. If the jam crinkles, setting point has been reached.
Mine did need the 3 hours but it very much depends on your slow cooker.
Transfer to sterilised jars and screw on lids.
Leave to cool.
Store in a cool dry place away from direct sunlight and once opened store in the fridge.