I have three varieties of plum trees in my yard. The earliest to ripen is the Santa Rosa. They look and smell so luscious, and then you bite into one. PUCKER!!!
The dark purple skin is so tempting, just buff off the natural, dusty “bloom” and reveal its glossy sheen. The mouth-watering sour will hit you like a brick wrapped in candy coating. When you get close to the pit, it isn’t any better. There’s only a thin layer of juiciness that is perfectly sweet. Some may say I’m exaggerating, but I’m not concerned with their frivolous opinions, only my own.
So what to do with those sour (to me) plums? Sugar is usually a good option. In fact, the varieties that are more sour are absolutely perfect for jams, syrups, and jellies. They naturally have higher pectin levels which help them set better with no added pectin needed, and the tart taste helps to offset the sugar added for these treats.
The birds tend to love these plums as much as we do. Unfortunately, they usually only peck away at one side, since that is what they can reach, and in the process also knock down several plums before they are quite ready. I cut away the pecked parts and use the rest without worry since they will be cooked at high heat. The under-ripe plums are allowed to “ripen” on the counter and are used as well. They won’t have as much flavor and definitely not as much sweetness, but they are a great source of pectin. Just be sure to use no more than 1/3 under-ripe plums or your product will be too sour and lacking in flavor.
Plum Jam Recipe
- plums (any variety, fresh or frozen), pitted and chopped in chunks
- granulated sugar
This plum jam recipe uses no added pectin (I don’t use it for any of my jams and jellies), just plums and sugar. One caveat: you do need to break the process up over two days, but they don’t have to be consecutive. The plums need to sit in the sugar to “macerate”, where the sugar causes the moisture to be sucked out of the plums. Don’t try to cheat and add water, you will only make the cooking process take longer and could cause the pectin to break down. Definitely don’t try to cook it right after the sugar is added, it will only burn due to not enough liquid (ask me how I know). Read here to see how to properly pit a plum without stabbing yourself, generally considered a bad thing.
For every 1 pound of pitted and chopped plums you will need 1/3 to 1/2 cup granulated sugar (use the smaller amount for sweeter plums, and the higher amount if they are more tart). The plums need to be cut in medium sized chunks. Once you have weighed your plums, put them in a non-reactive bowl and add the proper amount of sugar. Stir to mix completely, cover, and set aside. If you intend to make the jam the next day, leave the plums someplace cool, but not the refrigerator. If you need more time, you can put the plum mix in the refrigerator or even the freezer.
If you are new to the jam making process, be sure to read Food Canning 101. Once you are ready for the final jam making process below, put your clean jelly jars (always use more than you think you’ll need) into your water bath pot, cover pot and bring water to boil. You can reduce heat to a simmer while still covered to keep jars hot until you are ready. Put your flat lids into a small pot of water, bring to boil, and reduce to a simmer until ready to use.
Have a wide mouth funnel, cooling rack, ladle, and jar rings all ready to go. Don’t try to prep while your jelly is cooking or you may find yourself with either burned food or contaminated food. Neither is good.
You shouldn’t process more than 6 cups of the plum mix at a time unless you have a larger than usual sized stock pot. It adds too much time to the processing which can cause your pectin to break down, and you can also have the jam foam up too much where it can overflow the pot.
Place the plum mixture into a large stockpot fitted with a thermometer (see Food Canning 101!). Bring your liquid to a boil* stirring only occasionally to keep the pulp from burning on the bottom and continue to boil** until the gelling point is reached. This is 10 degrees above the boiling point of water at your elevation. For me at near sea-level, I remove my pot from the heat the moment it hits 222 degrees.
*Once your mixture reaches 5 degrees before your gelling point temperature, remove jars and flat lids from their water baths. Place both jars and lids upside down on a cooling rack to allow any water to drain. Make sure lids are not stacked on each other.
**If your jam threatens to foam over your pot, wave a wooden spoon through the bubbles to break them up. Do not stir! Just break up the bubbles.
Work quickly to fill jars and put the lids on them, one at a time. Screw the rings on snugly, and turn the jars upside down. This heats the lids and ensures that you will have a good and clean seal.
Once all jars are filled, flip each one back over carefully as they will still be hot. Set them somewhere out of the way to cool completely. Be patient, don’t try checking if they have set. If you keep messing with the jars they may not set at all! Once the jars are cool you should see that they have gelled. This can actually take a couple of days to get a complete set. Remove rings from lids, wipe down rims and rings with a clean, damp cloth, check that the flat lid is sealed well, and then replace rings. Any jars that didn’t seal, or any partially filled jars, should be placed in the refrigerator for immediate use. Enjoy!