I just made my own batch of cherry jam from the cherries I picked from my cherry tree in the front yard!
I made a really small batch (about 1/3 cup) because I wanted to make sure I could do it before I used all my hard-picked fruit.
This was so easy! You should try it - whether you picked the fruit yourself or not.
No-Recipe Cherry Jam
1. Buy as many cherries as you feel like pitting. Figure one pound of cherries will make one good-sized jar of jam. Plump, dark Bing cherries work really well, although Burlats are good, and if you can find sour cherries, your jam will rock.
2. Rinse the cherries and remove the stems. Using a cherry pitter, pit the cherries. Make sure to remove all the pits. Chop about ¾ of them into smaller pieces, but not too small. Leave some cherries whole so people can see later on how hard you worked pitting real cherries.
3. Cook the cherries in a large non-reactive stockpot. Add the zest and juice of one or two fresh lemons. Lemon juice adds pectin as well as acidity and will help the jam gel later on.
4. Cook the cherries, stirring once in a while with a heatproof spatula, until they’re wilted and completely soft, which may take about 20 minutes, depending on how much heat you give them.
5. Once they’re cooked, measure out how many cherries you have (including the juice.) Use 3/4 of the amount of sugar (if you have 4 cups of cooked cherry matter, add 3 cups of sugar).
6. Stir the sugar and the cherries in the pot and cook over moderate-to-high heat. The best jam is cooked quickly. While it’s cooking, put a small white plate in the freezer. Remain vigilant and stir the fruit often with a heatproof utensil.
7. Once the bubbles subside and the jam appears a bit thick and looks like it is beginning to gel, (it will coat the spatula in a clear, thick, jelly-like layer, but not too thick) turn off the heat and put a small amount of jam on the frozen plate and return to the freezer. After a few minutes, when you nudge it if it wrinkles, it’s done. If not, cook some more and test again.
8. Once it’s done and gelled, add a bit of cherry extract, which will highlight the flavor. Or add a few drops of almond extract. Ladle the warm jam into clean jars and cover. Cool at room temperature, then put in the refrigerator where it will keep for several months.
***I found the recipe here with its full narrative and pictures. Thanks, David Lebovitz!