A plum bonanza! Found this recipe by Jane Hornby on Good Food Magazine and it worked well (eventually after hours – literally – of boiling down). Below is my recipe adapted, based on comments on her recipe and my experience.
Weigh and then halve the plums (no need to remove stones) and cover with water in a robust deep pan. Simmer for about 45 minutes until pulpy and deep red in colour.
Remove the stones and then whizz the pulp with a stick blender. Stir in half the weight of jam (preserving) sugar ie if 2 kilo of plums, add 1 kilo of sugar. Once dissolved heat on high for about 25 minutes – be prepared for much longer if your plums are watery, it needs to be so thick that as you stir the spoon leaves a thick trail. Take care not to let the mixture catch on the bottom of the pan so keep stirring as it thickens.
Decant into silicone moulds or ramekins and keep chilled until you next have a posh cheeseboard.
This was soooo much easier than membrillo made with quinces.