Perfect Sour Cherry Jam

Ingredients

• 2 1/4 cups granulated sugar
• 2 1/4 teaspoons Pomona's Universal Pectin
• 3 pints sour cherries
• 1 tablespoon freshly squeezed lemon juice
• 3 teaspoons calcium water
• 1/4 teaspoon unsalted butter

Directions

1. In a medium bowl, whisk together the sugar and pectin. Pit the cherries, then put them in the bowl of a food processor. Pulse 8 to 10 times, just until the fruit is roughly chopped, not smooth. Measure out 4 cups of the chopped cherries and add them to a large, heavy-bottomed pot. Discard any extra cherries or save them for something else. Stir in the lemon juice and bring the fruit to a simmer. Cook, stirring now and then, until the cherry pieces soften and start to fall apart, about 10 minutes.
2. Add the calcium water and butter to the cherries, stirring them in, then bring the mixture to a boil. Pour in the sugar and pectin mixture and bring everything back to a boil, stirring the whole time. Once it is boiling vigorously, cook for 1 minute.
3. Take the pot off the heat and use a cold metal spoon to lift off any foam on top of the jam. Ladle the jam into hot sterilized jars, then process the jars in a hot water bath for 10 minutes.