Or rather jam today since I made the jam late last night out of one pound of cherry plums picked near the Water Eaton park and Ride on Monday (always good when you can incorporate a bit of fruit picking into the commute).
Wash and stone the cherry plums. I have to tell you that this is tricky as cherry plums are as small as cherries but their stones are as fiddly to extract as those of plums. It's the best of both worlds!
Weigh the stoned fruit, place in a saucepan with the juice of 1 lemon per pound of fruit (i.e. 1 pound of fruit = 1 lemon, 2 pounds = 2 lemons, etc.), and simmer until the juices start to run.
Add just over 1/2 the weight of the fruit in sugar and bring to the boil.
Continue to boil (stirring all the time to prevent burning) until the mixture goes thick and jammy*.
Pour into sterilized jars (I just put mine in a pan of boiling water and get them out using tongs and a tea towel) and leave to cool and set.
* it might be that we need a better thermometer (rather than the one we use for milk frothing) but I've never had any luck with either trying to get jam to the setting point of 104 C or doing put-it-on-a-cold-saucer-and-see-if-it-wrinkles thing.