My area is known for its sweet Flathead (Lambert) cherries, but I grew up with a pie cherry tree that I would climb into to pick its tart, bright red fruit—and often eat right within the branches. So let that warn you as to how tart I like my cherries.
If you’ve read the Canning Tools page, you may have noticed a slow cooker on the optional list. Fruit butters are entirely the reason. Fruit butters use both pulp and juice (unlike jelly) but let a long cooking time evaporate excess moisture and build dense texture and flavor (unlike jam). I use a slow cooker to make all fruit butters, which lengthens the cooking time but makes the process nearly hands off and burnproof. Add some spices to the reduction, and the cherries pop. If you have more cherries than your slow cooker can hold, set them aside for scones. Learn to make Tart Cherry Butter with Chai Spices and Sour Cream Scones with Tart Cherries