With only 4 ingredients, this simple blueberry butter is slow cooked for hours until thickened and is just perfect spread on your morning toast or bagel or spooned on top of yogurt or ice cream. The perfect way to preserve fresh blueberries and enjoy them all year long!
Add fresh blueberries to the pitcher of a blender or the bowl of a food processor and process until smooth.
Add pureed blueberries, sugar, cinnamon, lemon juice and lemon zest to a 6 quart or larger slow cooker and stir to combine.
Cover and cook on LOW for 1 hour.
Prop lid of slow cooker up with a wooden spoon or other heat-safe kitchen utensil to allow excess liquid to evaporate.
Continue cooking on LOW for an additional 4 to 5 hours checking on the blueberry butter every hour or so to see how thick it is.
Blueberry butter is done when it mounds nicely on a spoon and does not easily run off the spoon.
Once thickened, Ladle blueberry butter into a 1-pint canning jar or food storage container and store in the refrigerator for up to 2 months or in the freezer for up to 1 year.