I have two fairly large wild mexican plum trees (prunus mexicana) in front of my house, adjacent to the sidewalk. These drought tolerant trees are the first to bloom each spring with a showy display of white flowers. Towards the end of July the fruit begins to fall off the trees before it's fully ripe. The yellowish plums turn into a lovely reddish purple as they continue to ripen on the ground. This (mess) continues throughout September.
This year I picked about 2 pounds of plums and left them in a paper bag on my counter for a few days. At their ripest these small cherry-sized plums are still quite sour, but they make a wonderful tart jam.
|2 lbs wild mexican plums|
3 cups water
2-3 cups *sugar
Wash the plums, pick them over and place them into a heavy pot. Add the water and bring them to a boil for about 8-10 minutes. Turn off the heat.
When the plums are cool enough to handle remove a cupful at a time and place into a sieve placed over a bowl. Don't discard any of the water in the pot. Remove the seeds and press as much pulp though as you can. Continue until you have gone through all of the plums. Return the pulp mixture to the water in the pot. (I like to go through the discarded seed and skin mixture afterwards and pick out a few skins to return to the pot for their texture and colour, but this isn't necessary.)
Place a small plate into your freezer.
Add 2 cups of sugar to the plums and stir until it has dissolved. Taste. Add more sugar if the mixture is too tart. Bring to a boil, then reduce the heat a touch and simmer for about 20-30 minutes, skimming off any foam that forms.
Remove the cold plate from the freezer and place a teaspoonful of jam onto the dish. If the jam is too runny then simmer it for a few more minutes and try again. If you like its consistency, then ladle into hot sterilized jars, cover, cool and keep refrigerated.
If you plan on keeping the jam longer than 4-6 weeks, then ladle into hot sterilized jars leaving about a 1/2" head space. Cover with metal lids, and screw on the bands. Process in boiling water bath 8 minutes (extend this time to 15 minutes if your jars weren't hot and sterilized beforehand). Remove from the water and leave to cool.