Ingredients:
- 4 cups tart cherries, pitted (about 1 kg)
- 2 cups granulated sugar (400g)
- 1/4 cup freshly squeezed lemon juice (60ml)
- 1/2 teaspoon vanilla extract (optional)
- 1 packet (1.75 oz) fruit pectin (such as Certo)
- 4 (8 oz) glass jars with lids
Instructions:
- Sterilize jars by boiling them in water for 10 minutes, then let them dry completely.
- Wash and pit the tart cherries. If desired, chop them coarsely.
- In a large pot, combine the tart cherries, granulated sugar, and lemon juice. Let sit for 10 minutes to draw out juices.
- Bring mixture to a boil over medium heat, stirring frequently.
- Once boiling, stir in the fruit pectin. Cook at a rolling boil for 1-2 minutes, stirring constantly.
- Use a spoon or candy thermometer to check the jam's consistency. It should thickly coat the back of a spoon or reach about 220°F (104°C).
- Using a ladle and, if available, a canning funnel, fill the sterilized jars, leaving about 1/4 inch headspace.
- Wipe the rims clean and seal with lids. Process in a boiling water bath for 10 minutes for longer shelf life, if desired.
- Let jars cool undisturbed for 24 hours. Check seals before storing.