This seems to be my year to experiment with my slow cooker for making preserves. Today I decided to use all my remaining frozen blueberries to make blueberry butter.
I chose to pair it with my abundance of dried limes. Most blueberry butter recipes call for lemon zest and lemon juice, I decided to use ground dried lime and lime juice (you can use lime zest if you do not have dried limes).
The combination of the lime and blueberry flavors is wonderful; it taste both woodsy and sunny at the same time. The slow cooker makes the process fairly easy, albeit long. It took all day, so plan it for a hanging around the house day.
Blueberry-Lime Butter in the Slow Cooker
1.5 kg frozen blueberries ( or about 3 quarts fresh) (locally grown)
2 cups granulated sugar
1 tsp ground dried limes
2 Tbsp lime juice
2 tsp ground cinnamon
1/4 tsp ground nutmeg
Put the frozen blueberries in the slow cooker and cover. Cook on low for an hour, then use an immersion blender to puree the blueberries.
Cook on low for between 5 and 7 hours – keep the lid ajar with either a wooden spoon or chopsticks. Check the butter after 2 hours and then every hour to track the progress. When it starts to thicken (about an hour before you think it will be done, add the sugar, lime and spices. stir in and use an immersion blender again to smooth out the butter.
If you are getting ansty (like me) remove the lid and turn the slow cooker to high. But check on the butter and stir ever 10 minutes to prevent burning the butter. The butter is done when it is the texture of ketchup and spreadable.
When it is nearing completion, prepare a boiling water bath and sterilize 3 pint jars, 6 8-oz jars or a combination.
When the butter is done, turn off the slow cooker and ladle the butter into the prepared jars. Wipe the rims, apply the lids and rings and process in a boiling water bath for 10 minutes.
The sealed jars can be stored in a cool, dry place for up to 6 months. Enjoy!
Makes 3 pints.