This may sound silly, but I woke up a few days ago and realized that summer is nearly over, and I had not canned anything! Blueberries have been particularly lovely this year, so I wanted to make a fruit butter using them as the main ingredient. I added in some plums I had and then spiced them with some autumnal flavors to mark the impending change of seasons. The result is this Slow Cooker Spiced Blueberry Plum Butter!
Fruit butter is a jam-like product that doesn’t use any pectin, so it spreads easier than a normal jam or jelly. Fruit butters are best made by cooking the fruit low and slow, so a slow cooker is the perfect tool to make them! Although you are using a slow cooker, this recipe does require you to stir it every now and then, so you still have to stay close by.
I adapted this recipe from Food in Jar’s recipe for Slow Cooker Blueberry Butter. There are a few tools I find super helpful when canning, so I will link to those throughout this recipe, in case you wanted to know what I use.
Ingredients (makes about 5 pints, or 10 half pint jars):
- 6 pints blueberries
- 8 plums, quartered, pits removed
- 3 cups sugar
- the juice and zest of 2 lemons
- 1 tablespoon ground cinnamon
- 1 teaspoon ground cloves
- 1 teaspoon ground allspice
- 1 teaspoon ground cardamom
Wash your blueberries, picking out any leaves or stems. Wash your plums as well, and quarter, removing the pits.
In multiple batches (I think it took me 4 batches), add some of the blueberries and plums to a food processor or blender and puree. Pour into your slow cooker and repeat with the remaining blueberries and plums.
Cover your slow cooker and turn it on to high.
After an hour, stir the mixture and prop the lid so that there is room for some of the steam to escape.
Keep cooking the mixture for another 4 hours, stirring at least once an hour.
After 4 hours (or 5 hours of total cooking), stir in the sugar, lemon zest, lemon juice, cinnamon, cloves, allspice, and cardamom.
Remove the lid to your slow cooker and let cook for another hour or so, or until it reaches your desired thickness. (I aimed for the consistency of barbecue sauce).
If you are canning the butter, when the fruit butter is nearly finished, fill a very large pot with enough water to cover the jars by 1 to 2 inches. Wash your jars, lids, and bands in hot soapy water, rinsing them well and drying them thoroughly. Add the jars to the water and heat over high heat. (You want the jars to be warm when you fill them with the fruit butter.)
When ready to can, carefully remove the jars from the water. Fill each jar with the fruit butter, leaving a 1/2 inch of headspace.
Clean the rim and threads of each jar, using a clean, damp paper towel.
Add the lid on top of each jar, allowing the orange sealing compound to come in contact with the jar rim. Add the band and twist until it’s fingertip tight.
Add the jars to your pot, making sure that the water level covers to tops of the jars by at least 1 inch. Add boiling water if needed.
Add the lid to your pot and bring to a rolling boil. Process the jars for 10 minutes (it might be more if you live in a high altitude area).
When processing time is complete, turn off the heat and remove the lid. Let jars stand in the water for 5 more minutes.
Remove the jars from the canner (using a jar lifter if you have it) and set upright on a towel. This helps prevent jar breakage when the jar comes in contact with a cooler surface. Let jars sit for 12 to 24 hours. Do not tighten the bands during this time.
After 12 to 24 hours, check the lids for seals. The lids should not “pop” when the center is pressed. Remove the bands and try to lift the entire jar by the lid. If the lid stays on top, you have a good seal. If it doesn’t, refrigerate those jars and eat them sooner.
I like to label my jars so that I know what’s in them and also know what month I canned them.
Unopened jars should be stored in a cool dry place, and should be consumed within a year of making the fruit butter.
I opened up one of the jars to give it a taste and I am so happy that I did! The spices come through nicely, making this a perfect balance of summery blueberries and plums and autumn-inspired spices.
True to its name, the fruit butter is much easier to spread, and soaked nicely into the slice of brioche I ate it on. I’m sure we will enjoy this butter all through the fall!
Ingredients
- 6 pints blueberries
- 8 plums, quartered, pits removed
- 3 cups sugar
- the juice and zest of 2 lemons
- 1 tablespoon ground cinnamon
- 1 teaspoon ground cloves
- 1 teaspoon ground allspice
- 1 teaspoon ground cardamom
Instructions
- Wash your blueberries, picking out any leaves or stems. Wash your plums as well, and quarter, removing the pits.
- In multiple batches (I think it took me 4 batches), add some of the blueberries and plums to a food processor or blender and puree. Pour into your slow cooker and repeat with the remaining blueberries and plums.
- Cover your slow cooker and turn it on to high.
- After an hour, stir the mixture and prop the lid so that there is room for some of the steam to escape.
- Keep cooking the mixture for another 4 hours, stirring at least once an hour.
- After 4 hours (or 5 hours of total cooking), stir in the sugar, lemon zest, lemon juice, cinnamon, cloves, allspice, and cardamom.
- Remove the lid to your slow cooker and let cook for another hour or so, or until it reaches your desired thickness. (I aimed for the consistency of barbecue sauce).
- If you are canning the butter, when the fruit butter is nearly finished, fill a very large pot with enough water to cover the jars by 1 to 2 inches. Wash your jars, lids, and bands in hot soapy water, rinsing them well and drying them thoroughly. Add the jars to the water and heat over high heat. (You want the jars to be warm when you fill them with the fruit butter.)
- When ready to can, carefully remove the jars from the water. Fill each jar with the fruit butter, leaving a 1/2 inch of headspace.
- Clean the rim and threads of each jar, using a clean, damp paper towel.
- Add the lid on top of each jar, allowing the orange sealing compound to come in contact with the jar rim. Add the band and twist until it's fingertip tight.
- Add the jars to your pot, making sure that the water level covers to tops of the jars by at least 1 inch. Add boiling water if needed.
- Add the lid to your pot and bring to a rolling boil. Process the jars for 10 minutes (it might be more if you live in a high altitude area).
- When processing time is complete, turn off the heat and remove the lid. Let jars stand in the water for 5 more minutes.
- Remove the jars from the canner (using a jar lifter if you have it) and set upright on a towel. This helps prevent jar breakage when the jar comes in contact with a cooler surface. Let jars sit for 12 to 24 hours. Do not tighten the bands during this time.
- After 12 to 24 hours, check the lids for seals. The lids should not “pop” when the center is pressed. Remove the bands and try to lift the entire jar by the lid. If the lid stays on top, you have a good seal. If it doesn't, refrigerate those jars and eat them sooner.
- I like to label my jars so that I know what's in them and also know what month I canned them.
- Unopened jars should be stored in a cool dry place, and should be consumed within a year of making the fruit butter.
What do you think?