Italian Plum Jam

Posted on August 19, 2012


Yardlong or Chinese Long beans in the Learning Garden

With a full “day off” ahead of me- gardening at the farm and in my tiny (and sorely neglected) GROW plot, and seeing the one and only John Prine perform later tonight- I’m going to (try to) keep this one on the short side.

Stanley plums

I’ve been holding out for bulk-priced plums for what has felt like forever. The incredibly-luscious, sweet and succulent early plums, suspected to be Myrobalan or cherry plums, of July were great for fresh eating, but they were also pretty expensive, only being sold by pint and quart. Even more, their availability didn’t last long at my local farmers market; I suspect this crop was hit by the early spring frosts that wreaked havoc on many stone fruit crops in the Northeast.

The first of the Brandywine heirlooms in the Learning Garden

However, this past week at the Central Square market I spotted some Italian plums (Stanley variety) from Kimball’s Farm. Priced at $4 per pound, I was hesitant to hold out for a lower price in the coming week or so. BUT I also reaaaally wanted to get going on the late summer portion of my can plan. Corn and tomatoes are just now starting to come in and bulk up, so those guys could wait. And so I bought several pounds of these firm-bodied beauties to be cooked down into a simple and gorgeous plum jam.

Stanley plums

Italian or prune plums, much like paste tomatoes, have a lower water content than other cultivars, making them more suitable for canning. While they can certainly be eaten fresh, their flavor truly shines when jammed or stewed. After halving, pitting, and chopping them up, I had about 5.5 pounds of plum flesh to deal with, but only 2 cups of sugar in my house. This was A-okay with me though, as I am getting more comfortable with the idea of creating my own, lower-sugar recipes for high-acid fruits. I must say, this is the first canned batch in which I did not follow a recipe*, and I’m extremely satisfied with the results. While you can certainly cook it to the gelling point (220°F at sea level), I cooked mine to about 216°F (thankyouverymuch, new digital thermometer) for an oh-so-slightly looser set. It’s still got body, but absolutely no Jello-quality to it.

Plum jam on spoon and plate

*Rest assured, I did comb through the conservative National Center for Home Food Preservation website to ensure the safety of this recipe. Plums are a high-acid food that do not need added acidity to safely can in a hot water bath canner. While sugar does act as a preservative, it is not necessary for the safety of the preserve.

Italian plum jam

Italian Plum Jam

Makes about 8 half-pints (I used quarter-pint jars)


  • about 5.5 lbs Italian plums, washed, halved, pitted, and chopped
  • about 2 cups sugar


Plums macerating in sugar

Combine all ingredients; allow the prepped plums to macerate in the refrigerator for 12-24 hours in a non-reactive pot. Bring the mixture slowly to a boil, then cook rapidly to, or almost to, the gelling point (again, 220°F at sea level). Stir constantly to prevent sticking or burning. Ladle hot jam into sterilized half or quarter pint jars, leaving 1/4″ headspace; process for 10 minutes in a boiling water bath canner.