Creating Slow Cooker Blueberry Butter is straightforward with these clear steps:

1. Prepare Blueberries: Place the washed blueberries into the slow cooker, ensuring they are evenly distributed.
2. Add Ingredients: Sprinkle the sugar, lemon juice, cinnamon (if using), vanilla extract, and salt over the blueberries.
3. Mix Gently: Use a wooden spoon to mix the ingredients, ensuring the blueberries are coated evenly with the sugar and spices.
4. Set Slow Cooker: Cover the slow cooker and set it to low heat. Let it cook for 6 to 8 hours, stirring occasionally as needed.
5. Check Consistency: After cooking, check the consistency of the blueberry mixture. If it is too liquid, continue cooking, uncovered, for an additional hour or until it thickens.
6. Blend for Smoothness: For a smoother butter, use an immersion blender to blend the mixture until desired consistency is reached.
7. Cool: Allow the blueberry butter to cool for about 30 minutes before transferring it to jars.
8. Store: Pour the cooled butter into airtight jars, seal them tightly, and store in the refrigerator for up to 3 weeks.

These simple steps will guide you in producing a batch of blueberry butter that is both delicious and versatile. The flavors will enhance over time as the butter sits, making it even more delightful!