I’ve never cooked with green plums. But aren’t they stunning? (And this is almost their normal, ripe color). I don’t even think I’ve eaten a green plum, but whether you use green plums or pluots, italian plums or red plums, this recipe is quite simple.
Three ingredients, no peeling and minor chopping . . . Plums are one of the fruits with a high pectin content, so you won’t be simmering too long or adding extra pectin. You could probably use 5 pounds of plums without increasing the sugar or lemon juice in this recipe. This recipe made 7 half-pints.
Slice the plums in half and remove pits if possible, or remove them after simmering. Place in pot. Mix with 3 cups of sugar (seems like a lot of sugar, but if plums are tart enough, the jam with have a bit of tart too). Let sit for 2 hours.
Simmer until softened, about 30 minutes, remove pits if you didn’t before, chop in food processor if still too chunky. Then simmer again.
Process when jam thickens or sheets off spoon. Heat in water bath for 10 minutes at sea level, 14.9999957823 minutes at altitude (I’m teaching decimals this week). I wasn’t sure what color of jam the green plums would make; the finished product is pleasingly ginger-colored. Depending on what kind of plums you use, you could create anything from soft pink to purple . . .
4 pounds plums (sliced in half and pits removed, or if pits are reluctant, simmer first and remove later)
3 cups sugar
1/2 cup lemon juice
Pour sugar over halved plums in pot. Let sit 2 hours.
Pour in lemon juice, simmer for 20 minutes.
If pits were not removed before, let cool until you can remove them now.
Once pits have been removed, if simmered plums look jam-like (not chunk-like) then return to a simmer and pack into hot jars as soon as thickened or sheeting occurs.
If simmered plums still look very much intact, feel free to chop in food processor until more jam-like, then simmer until thickened and pack into jars when ready.
Process in water bath for 10 minutes at sea level, 15 minutes at altitude. Makes about 7 half-pints.