Wash the cherries, remove the stems, and remove the pits. Coarsely chop the cherries. Measure out 4 cups of chopped cherries.
COOK
In a large saucepan or Dutch oven over medium-high heat, bring the cherries, sugar, lemon juice, and almond extract (if using) to a boil, stirring until the sugar dissolves. Stir in the liquid pectin. Bring the mixture to a rolling boil that cannot be stirred down. Boil hard for exactly 1 minute, stirring constantly. Remove the pot from the heat; skim off any foam.
FILL
Ladle the hot jam into hot sterilized jars, leaving ¼-inch of headspace at the top of each jar. Wipe the rims clean with a damp cloth, then secure the lids and bands so that the bands are fingertip-tight.
PROCESS
Process half-pint jars in a water bath for 15 minutes. Make sure that the jars are covered by at least 1 inch of water.
Carefully remove the jars to a towel on the counter. Let stand, undisturbed, for 12 hours at room temperature. Check the seals after 12 hours by pressing the center of the lids. If the lid gives or the center button remains popped up, store in the refrigerator for up to 1 month. Properly sealed jars will keep in a cool, dark place for up to 8 months. Refrigerate after opening.
Notes
Recipe slightly adapted from Ball Guide to Preserving.
If using sour cherries instead of sweet cherries, omit the lemon juice.
It’s a good practice to sterilize the jars and lids before canning in order to kill any bacteria, fungi, or yeast. There are a variety of ways to sterilize the jars (here’s a helpful article with different options). I typically use the dishwasher, or just boil them for 10 minutes in the same big pot of water that I’ll use for processing.