How to make plum jam

This plum jam recipe is easy enough to make on a weeknight if you’re an experienced jammaker, or on a weekend if you’re a novice. You’ll enjoy the sweet tart taste of summer all winter long.

Last week the plums started arriving at work, in bags and baskets, distributed to various strategic places in offices and common area. Piles of fruit, in tones from deep purple to a delicate mottled green, enticing all of us to stop and nibble on one or to grab a handful for later.

It is plum season in Seattle, and so many people have trees in their yard producing a bountiful harvest of fruit. My plum trees are old and gnarled, covered in lichen. I haven’t seen any fruit from them in years. They are still beautiful, though useless. So when one of my coworkers, perhaps with a tone of slight despair over the quantity of fruit his trees were producing, offered to bring me a whole bag of plums, I eagerly accepted. I would make jam, I said, and would bring him back a jar of it.

The plums duly arrived the next morning. Ripe fruit does not wait, so I stopped on the way home for some extra lids and pectin, and got out my canning tools.

I have made enough jam by this point to know that it can be done in a few hours on a weeknight, should the need arise. But that is without any dallying, or I will end up still in the steamy kitchen, sticky-haired and cross, after my usual bedtime.

So without loss of time, I gathered up jars and rings and canning utensils got them in the dishwasher. And I filled the big canner and put it on the stove, as that much water takes nearly forever to come to a boil.

Then I took a moment to consider recipes. Jam is just fruit, water, sugar, pectin and heat, in varying ratios. I knew I wanted a basic reduced-sugar recipe, so that the bright tartness of the fruit would not be overwhelmed. The big controversy in plum jam recipes is whether to peel the plums. Some cooks contend that the peels become tough and bitter. Others leave the peels on and are quite happy with the results. I applied Occam’s Razor to this problem and took the simplest course. I left the peels on.

And my jam was all that I hoped it would be. A delicate glowing ruby color. A medium set – not hard and jelly-like, but nicely jammy (perhaps a circular definition, but this is cooking, not rhetoric!). And sweet, but not a sugarfest. The summery tart flavor of the plums asserted itself exactly as I had hoped.

And there were even a few halved pitted plums left over, to put in the refrigerator and eat over the next few days whenever I walked past, with a little shiver of pleasure as the icy fruit touched my tongue. Just as William Carlos Williams points out in his poem "This Is Just to Say", they were delicious. So sweet and so cold.

Plum Jam

(Adapted from Sure-Jell recipe) 

 7 cups pitted and finely diced plums, peels left on (buy about 4 pounds of ripe plums and eat any extras)
1/2 cup water
4-1/2 cups sugar, divided
1 box low sugar/no sugar powdered pectin

Bring canner, half full with water, to simmer. Wash eight 8-ounce jars and screw bands in dishwasher to sterilize. Leave in dishwasher until ready to use. Place flat lids in small saucepan, cover with water, and bring to a gentle simmer. Turn off heat and let stand in hot water until ready to use.

Take 1/4 cup of the sugar and mix with the pectin in a separate small bowl. Set aside.

Pit unpeeled plums. Finely chop fruit. Place fruit in saucepan and add water. Bring to boil. Reduce heat to medium-low. Simmer for 5-10 minutes (until they look soft and cooked), stirring occasionally and mash a bit with a potato masher. Measure exactly 6-1/2 cups prepared fruit into a heavy-bottomed stockpot.

Add pectin/sugar mixture to fruit in stock pot. Bring to full rolling boil (a boil that doesn’t stop bubbling when stirred) on high heat, stirring constantly. Stir in remaining 4-1/4 cups sugar. Return to full rolling boil and boil exactly 1 minute, stirring constantly. Remove from heat. Let sit for 2 minutes, stirring occasionally and skimming off any foam with a metal spoon.

(Save the foam! It is delicious. Put it in the refrigerator and use it within a few days. Stir it into your yogurt, put it on your ice cream, or just use it like jam. It is jam really, just foamier.)

Ladle into prepared jars, filling to within 1/8 inch of tops. Run a butter knife around inside of jars to remove air pockets. Wipe jar rims and threads. Cover with lids. Screw bands on tightly. Place jars on rack in canner. Water must cover jars by 1 to 2 inches. Add boiling water, if necessary. Cover and bring water to gentle boil. Process for 10 minutes.

Remove jars and place upright on a towel to cool completely. After jars cool, check seals by pressing middles of lids with finger. (If lids spring back, lids are not sealed and refrigeration is necessary.)