Step 1

Dump blueberries into the slow cooker and set cooker on high for 90 minutes.

Step 2

Take off lid and cook for another 30 minutes on low.

Step 3

Hand blender to puree the blueberries right in the slow cooker. Or transfer blueberries to regular blender and blend then pour back in the slow cooker.

Step 4

Put the lid back on the slow cooker leaving it slightly cracked to allow air to escape. Cook for another 3 hours on low. Stir every hour.

Step 5

Now stir brown sugar, nutmeg, allspice, cinnamon and lemon juice until combined.

Step 6

Replace lid, again leaving a small crack in lid to allow air to escape. Over the next hour, the blueberry butter should thicken to your desired consistency.

Step 7

Pour butter into jars and allow to cool before refrigerating. Properly refrigerated, blueberry butter will keep for 7-10 days.