When we were kids we made plum jam every year with our godmother Neva. It was an all day event: Neva would come over in the morning and we would collect plums from the trees all over our neighborhood. We’d hold an old sheet under the trees and Neva would rattle the branches with an extendable stick we called The Plum Basher until the plums fell down, mostly on our heads. When we’d caught enough plums in the blanket we’d bring them home to cook the jam, which is where my memory of how to make plum jam ends. As I recall, Neva did something magical involving a lot of cooking and squishing and straining and stirring, while we made elaborate labels and ate the warm jam foam she skimmed off the top of the pot.
This past week I’ve tried to reconstruct Neva’s plum jam recipe. I had my limited memories, some notes I took the last time we made it together, and the Joy of Cooking. It took two tries, and I ended up making jelly rather than jam, but it’s delicious. The key, I think, is to get some young assistants to help with the bashing and straining. I couldn’t do it on my own, but with help from Kate and Clara, we made a lovely plum jelly.
More seriously, I think Neva’s recipe is meant for the small plums that grow in our neighborhood. On Monday I tried to use plums from my mom’s new tree (a mere decade old) which has big fruit like you see in stores. The fruit is sweet and delicious for eating, but you don’t really want to add any sugar to it. It also barely scraped by in the pectin test and after cooking it didn’t have much plumy flavor, it was just vaguely fruity syrup. No good at all. If you have plums like that and want to make jam, you’ll want a different recipe and probably some packaged pectin. So when I tried again I gathered up a plum bashing team and collected the little plums we used to use. Much better.
Neva’s Plum Jam
Makes 4-8 cups of jam, depending on how many plums you start with
A large basketful of barely ripe 1″ plums
2-4 cups of sugar
Wash the plums. Dump the clean whole plums into a heavy pot over medium heat. Stir and squish down the plums to let the juice out (a potato masher is great for this, but the back of a big spoon will do). Cook until all the plums are soft and smashed.
Drain the juice through a sieve (top right picture above), stirring to let all the liquid out. Neva would scrape the skins against the metal of the sieve with the back of a spoon to get out all the meat of the plums, which makes a thicker, cloudy, more flavorful jam. Since Kate and Clara were doing this step we stirred but did not scrape, which makes something closer to a jelly. I like to do one big ladle-full (about 2 cups) at a time, and dump all the skins and pits into the compost between scoops so they don’t block up the holes of the sieve.
Test the juice for pectin. In a jar, shake a tablespoon of plum juice with a tablespoon of rubbing alcohol. Does it set? If there is pectin in the juice, it should form a big blob or two. If it doesn’t do this, you need to add pectin. Get a package of the reduced sugar stuff, and follow the directions inside.
Put a couple of little plates in the freezer. You’ll use them later to test whether your jam is done.
If your juice passed the pectin test, measure the plum juice back into the pot. Add as much sugar as juice and bring to a boil (bottom left picture above). The jam must boil or it will not set. Turn down the heat and simmer. A cloudy layer of bubbles will form at the top of the jam. Skim this foam off the top and drop it in a bowl for your assistants to dip bread in.
Starting after about half an hour, test whether the jam is done by putting a spoonful onto one of your frozen plates. Roll it around until the jam has cooled, then run a finger through it. If your finger leaves a clean trail and the jam feels solid and jammy, it’s done. If not, keep cooking. It has taken us as long as two hours before the jam is done, so don’t worry!