For starters, note that this does NOT preclude these preserves as being used like jam, but technically, they're preserves, or so the ladies at the State Fair will remind you. Just FYI.

Via Epicurious

• 4 lb sour cherries, stemmed and pitted, reserving 3 tablespoons pits
• 5 cups sugar (I think the 2017 version should use 4 c sugar)
• 1/3 cup fresh lemon juice
• Pomona's pectin, double the amount for the basic cherry jam = 4 tsp pectin & 4 tsp calcium water (if you want a less jammy consistency, use half this)

Toss together cherries, sugar, and lemon juice in a large bowl.

Wrap cherry pits in a paper towel and crack them with a rolling pin or pestle just enough to extract inner white kernels. Tie kernels in a cheesecloth bag. Stir bag into cherry mixture and chill, covered, overnight.

Sterilize jars and lids .

Pour cherries with liquid and cheesecloth bag into a 5- to 6-quart heavy pot (sugar will not be completely dissolved). Bring to a rolling boil over moderate heat, then boil, uncovered, stirring frequently, 5 minutes.

Remove from heat and transfer cherries with a slotted spoon to a sieve set over a bowl to catch juice. Drain cherries 5 minutes, then add juice from bowl to juice in pot.

Get your jars ready.

Divide cherries among jars using a slotted spoon.

Return juice in pot to a rolling boil, skimming off any foam. Continue boiling until juice registers 220 to 224°F on thermometer, 7 to 10 minutes. Discard cheesecloth bag.

Gradually add pectin, whisking constantly. Return juice to a rolling boil, then boil, skimming off any foam, 1 minute. Ladle juice into jars, leaving 1/4 inch of space at top, then run a thin knife between fruit and jar to eliminate air bubbles.

Seal, process, and store filled jars , boiling preserves in jars 10 minutes.