1. Begin by washing and hulling the berries. If using strawberries, cut them into quarters.
2. Place the berries in the slow cooker and mash them slightly with a potato masher to release their juices.
3. Add the sugar and lemon juice to the slow cooker, stirring to combine.
4. Cover and cook on high for 2 hours, stirring occasionally.
5. After 2 hours, stir in the fruit pectin and continue to cook on high for another 30 minutes.
6. Once the jam has thickened, ladle it into sterilized jars, leaving about 1/4 inch of headspace.
7. Seal the jars with lids and process them in a boiling water bath for 10 minutes to ensure a proper seal.
8. Allow the jars to cool completely before storing them in a cool, dark place.
Variations & Tips
Feel free to experiment with different fruit combinations, such as peaches and blackberries or apricots and cherries. For a spiced version, add a cinnamon stick or a few cloves to the slow cooker. If you prefer a smoother jam, use an immersion blender to puree the mixture before adding the pectin. Remember, the key to a good jam is balancing sweetness with the natural tartness of the fruit, so adjust the sugar to your taste.
