Ingredients
Here’s a breakdown of what goes into this rich, silky blueberry butter and why each ingredient matters.
For the Blueberry Butter
- 8 cups fresh or frozen blueberries — The star of the recipe, providing natural sweetness and that signature deep purple color and flavor.
- 1½ cups granulated sugar — Sweetens the spread while helping it thicken and develop the right texture as it cooks down.
- ½ cup light brown sugar — Adds a deeper, slightly caramelized sweetness alongside the granulated sugar.
- 2 tbsp fresh lemon juice — Adds brightness and balances the sweetness of the blueberries and sugar.
- 1 tsp lemon zest — Contributes fresh, aromatic citrus flavor throughout the spread.
- 1 tsp ground cinnamon — Adds warm, cozy spice that complements the sweetness of the blueberries.
- ¼ tsp ground nutmeg — Adds a subtle, warm depth typical of classic fruit butter flavor.
- 1 tsp vanilla extract — Rounds out the flavor with warm, aromatic sweetness.
- ¼ tsp kosher salt — Enhances all the other flavors and balances the sweetness.
Optional Add-Ins
This recipe is easy to customize with additional warm spices or flavor twists. Consider adding:
- 1 tbsp fresh grated ginger (for a warm, spicy kick)
- ½ tsp ground cardamom (for an aromatic, slightly floral note)
- 1 cinnamon stick (for a more subtle, infused cinnamon flavor)
- 1 tsp orange zest (for added citrus brightness alongside the lemon)
- 1 tbsp maple syrup (for a deeper, more complex sweetness)
- 1 tsp lavender buds, culinary grade (for a delicate floral twist)
- 1 tbsp bourbon (for a warm, boozy depth of flavor)
Instructions
This recipe involves a long, slow cook followed by blending and a final reduction. Here’s exactly how to make it.
Add the blueberries, granulated sugar, brown sugar, lemon juice, lemon zest, cinnamon, nutmeg, and kosher salt to a 6-quart slow cooker.
Stir the mixture well to ensure the sugar and spices are evenly distributed throughout the blueberries.
Cover and cook on HIGH for 3–4 hours or LOW for 6–7 hours, stirring once or twice during cooking, until the blueberries have completely broken down and softened.
Using an immersion blender, blend the mixture directly in the slow cooker until completely smooth. Alternatively, carefully transfer the mixture to a blender in batches and blend until silky, then return it to the slow cooker.
Leave the slow cooker uncovered and continue cooking on HIGH for 1–2 hours, stirring every 20–30 minutes, until the mixture has reduced and thickened to a spreadable consistency.
Stir in the vanilla extract during the final 10 minutes of cooking, allowing it to infuse into the finished spread without cooking off its flavor.
To test whether the blueberry butter is ready, spoon a small amount onto a chilled plate. If it holds its shape without excess liquid spreading around it, it’s fully reduced and ready to jar.
Ladle the hot blueberry butter into clean, sterilized jars, leaving about ¼ inch of headspace at the top of each jar.
Allow the jars to cool completely before refrigerating. For shelf-stable storage, process the filled jars in a boiling water bath according to safe home canning guidelines.