Microwave tricks: 5-Minute Plum Jam for Fall

These Italian prunes are some of the fresher, better-looking specimens from my greengrocer’s bin this week. But overripe plums work fine too.

Italian blue or prune plums are probably the last round of plums to appear at my local greengrocers for the year (well, until they start getting in carboys of plums and peaches from Chile). Prune plums aren’t much to look at–well, okay, they have a graceful enough elongated shape, but cut into one and you won’t be terribly impressed–the peel is thick and slightly bitter, the flesh is yellow-brownish, not very juicy, and a bit stickier and less brilliantly flavored than the red and black plums of summer, to say nothing of the gorgeous green and mottled dinosaur and Santa Rosa plums we can get here in LA. Many of the fresh prunes end up overripe and still untaken at the end of the day.

Which, I’ve discovered this week, is actually quite a shame. Because if you buy them early and firm, while there’s still a tint of reddish purple about them, they’re closer to regular plums–crisper, juicier and livelier tasting raw. Still not the ideal eating plum, but not bad.

And if you take the ones that are fully ripe and disappointing and bland and not too pretty, cut them up and microwave them, suddenly everything transforms. Italian prune plums make a gorgeous, rose-red, vibrantly flavored low-sugar jam. A lot like cranberry sauce in both color and flavor, but somehow a little mellower, with the bitter edge off, and a hint of spicy perfumed depth.

Five minutes in the microwave, and everything changes.

Many stone fruits react this way to heat–sometimes sugar too, but mostly it’s the heat. Even very bland, mushy pale apricots seem to bloom into vibrant flavor and acidity when baked or simmered, and sour cherries go from slightly bitter and dull raw to world-famous classic pie filling with a strong almond aroma. I’ve rescued bland, spongy supermarket nectarines and peaches by microwaving them into fruit spreads with real flavor, but obviously good fruit makes even better jams and compotes. It’s just that when the fruit is good raw, I’d usually rather eat it raw, because the season is short.

The prune plums I bought this past week don’t provoke that dilemma of choice; they’re definitely better turned into a quick fruit spread, and maybe I’ll freeze a second batch for later. These plums would also make a great pie filling, like the zwetchgenkuchen that Joan Nathan first published as a traditional German Jewish dessert for Rosh Hashanah in The Jewish Holiday Kitchen. Baked conventionally, the quartered prune plums would probably hold their shape somewhat in the crust and look beautiful.

In the microwave, the plums quickly break down to a bubbling mass and gradually take on color from the peel–at first, bronze with a hint of pink, and after a minute or two the color spreads and deepens to cranberry red (as does the flavor). Sugar just to taste, a tiny squeeze of lemon, and a pinch each of clove and ginger balance out the tartness, and after a day in the fridge, the jam has mellowed and integrated beautifully.

The accents of brandy, cinnamon, nutmeg and lemon peel in Nathan’s recipe make me want to run back to the store and try it this instant, but after a week of baking challah for the high holidays and prospects for 100 degree temperatures yet again, I’m not sure today’s the day. Maybe for Sukkot, which starts later this week.

But the combination of plums with aromatic spices is right on, and if you’re adventurous you could always take this fruit spread one step further and add a small spoonful of brandy, a few shakes of cinnamon and an even tinier hint of nutmeg, even a little grated lemon peel. The simple version below is good on toast, delicious with Greek yogurt and plenty complex enough for me before or after the second cup of coffee.

However, the full-on dressed-up version would probably be a wonderful accent for goat cheese tartlets or a baked brie if you were doing swanky appetizers for a dinner party. I’d test-taste a small batch of the jam first just to make sure it wasn’t too rich with the brandy and nutmeg, because a little goes a long way, but otherwise, let ‘er rip. The plum-jam-with-cheese appetizers would also be an unexpectedly good accompaniment to mead, sherry or other apéritifs for fall.

5-Minute Microwave Plum Fruit Spread (makes about a cup)

• 5-6 ripe Italian blue or prune plums (or any other plums), washed, pitted and cut up
• 2-3 T sugar (or more to taste–I like mine less sweet, more fruit)
• squeeze of lemon juice
• pinch of cloves (maybe 1/8 t, probably a little less)
• pinch of powdered ginger (a little less than 1/8 t)

Put all ingredients in a microwaveable ceramic bowl big enough to hold them with a couple of inches to spare, because the plum mixture will bubble up as it cooks. Remember to handle the edges of the bowl with a towel or oven mitt or something (folded paper sandwich bags also work okay in a pinch) because this will heat long enough for the bowl itself to get hot.

Microwave 1-2 minutes on HIGH (I have an 1100 W oven, so adjust times to whatever works for you if yours is older and lower power). The plums should be starting to break down and just starting to color pinkish. Stir the mixture and microwave another minute or so, stir again. If it’s not cooked as much as you think it should be, microwave another minute or so but be prepared to hit the stop button if you see it start to boil over. If it’s fully colored and broken down to a fruit spread, take a small spoonful, let it cool, and taste carefully. It will probably taste a lot like not-very-sweetened cranberry sauce. If it’s not sweet enough for you, add a little more sugar to taste, and maybe another squeeze of lemon, then let it cool all the way covered and refrigerate. It will thicken a little further and mellow overnight and taste more like plums, especially with the clove and ginger notes.

You can, obviously, also boil the ingredients a few minutes in a saucepan on the stovetop if you prefer. If you want it completely smooth, cool it and put it through a food mill or food processor.

This isn’t canned, so store it in the fridge for up to a week or freeze it for later. When you thaw it, taste it again–you might need to add another squeeze of lemon and/or reheat in the microwave just a minute or so to refresh it.