plum jam
A few days ago we had a chance encounter with a local farmer trying to off-load his market leftovers in a back alley. $20 later, we were walking home with a case of plums. A whole case! As it turns out, that is a lot of plums.
We made twenty 8 oz. jars (2 batches) of plum jam, a plum crisp and a couple pints of plum syrup for flavoring kombucha & water kefir soda. We sautéed plums in butter and ate them on top of a dutch baby pancake. Obviously, we ate them straight up. And we still have 30 or 40 plums to go!
I think plums are often overlooked. Everyone goes gaga over peaches (myself included) and the poor plums sit on the sideline, "fine, underestimate me..." they think. But plums make a fine jam, among other things (I highly recommend the plum crisp). More than other fruits, I think, plums lend themselves to some creative flavoring options, if that kind of thing gets your heart beating: vanilla, cardamom, nutmeg, jalapeño, basil, anise, just to brainstorm a few. There are a ton of varieties of plums as well, all with different flavor profiles, skin & meat colors. I was particularly pleased with the beautiful rosy color of this jam, though I can't recall the name of the plum variety.
how to make plum jam
There are a few different schools of thought when it comes to making jam. Some people don't want to use pectin because, well, wtf is pectin? I get it. Unless you're super hardcore, pectin is a mysterious white powder you buy at the hardware store. But pectin is naturally derived. There is naturally-occurring pectin in all fruit. You can make it yourself by boiling down crab apples (amongst the fruit kingdom, they are exceptionally high in pectin). Pectin reacts with sugar to create the gelling effect that is inherent to jam. If you don't add pectin, you'll have to boil the living crap out of your fruit to increase the relative pectin levels enough to gel. Plums do have more naturally-occurring pectin than the other stone fruits, but pectin levels also decrease as the fruit ripens, and if you ask me, I'd much rather preserve the flavor of fully ripe plums than hard, underripe plums. And I like my jam as fresh tasting as possible. Also, I'd rather not spend my summer crouched over a boiling, spitting pot of sugar fruit glop.
My school of thought, and the school of thought reflected in this recipe is: I want to reduce the amount of added sugar by using low-sugar pectin and cook my fruit for as little time as possible in order to create the environment for proper gelling. This makes for a jam that tastes fresh from the orchard, all winter long. I did find, to my surprise, that for some reason plum jam and plum jam alone requires the same amount of sugar whether you're using regular pectin or low-sugar pectin, according to Sure-Jell. If you want to further reduce the amount of sugar, try the recipe from Ball using grape juice instead of granulated sugar (I don't usually go for the grape juice because it means running out to the store to buy grape juice, when I've got plenty of perfectly good cane sugar right here).
what you'll need
10 half-pint canning jars with new lids
Canning kit or:
Stock pot
Canning rack, vegetable steamer or other device for keeping jars off the bottom of the pot
Tongs
the recipe
3 pounds ripe plums (6.5 cups crushed)
4.5 cups sugar
1 box (regular or low-sugar) Sure-Jell brand pectin, 3 Tbsp. low-sugar, or 6 Tbsp. classic Ball brand pectin
1 Tbsp. butter
Optional: flavorings for exciting and unusual jams!
A few ideas: balsamic vinegar, vanilla bean, cardamom, nutmeg, basil, jalapeño, anise, etc.
1. Fill your canning pot with enough water to cover jars. Place clean jars (without lids or bands) in and bring to a boil to sterilize. Always sterilize a couple more jars than you think you'll need, just in case. Boil for 10 minutes.
2. Meanwhile, prepare your plums. Remove pits by slicing the meat away from the pit. Plum meat doesn't separate from the pit easily, the way peaches do.
3. Pulse in food processor until desired consistency is reached. Naturally, the chunkier you leave it, the chunkier your finished jam will be. Because of the short cook time, the fruit won't break down a whole lot during cooking.
4. Transfer plums to a pot. Don't skimp on the size of the pot, or you may get burned! Add pectin to crushed fruit and stir well.
5. Heat over medium-high heat and bring to a hard rolling boil. (A hard rolling boil is one that does not calm when stirred) Boil for 1 minute.
6. Add sugar & butter. If yours is foamy, the butter (or any fat) is added to reduce this foam. Jammers usually call it scum, but I'm not down with that. Scum makes it sound so dirty. (In this image you can see some yellow foam still lingering around the edge of the pot)
7. Bring back to a hard rolling boil. Stir and boil for 1 minute.
8. Remove from heat. If foam appears at the top of the pan, remove with a spoon.
9. Place lids in boiling bath for ~30 seconds. Remove hot jars & lids from bath. It is important that every component is nice and hot, lest you shatter your jars. Jars, jam and water bath should all be piping hot when you put them back in the water bath to seal.
10. Fill sterilized jars with the hot jam. Pass a butter knife around the perimeter of the jar to remove air bubbles. Cover with a lid & band.
11. Place full jars in bath to seal. Once water bath has returned to a strong boil, process half pints for 5 minutes & pints for 10 minutes.
12. Remove jars. As they cool, you should start hearing little metallic pings going off. This is a vacuum-like suction sucking the lids in as the contents of the jar reduce in size from the change in temperature. After each jar pings, the safety seal button built into the lids should be taut, concave, and inflexible when tapped. This is how you know you've gotten a good seal. If any have not sealed properly, put them in the fridge and use them first.
In this photo, the jar in the front left has already pinged and I can tell it's a good seal. The one on the right is still somewhat convex--it hasn't pinged yet, but did soon after.
Beautiful color, right?!
Happy summer!
Melody