This easy slow cooker blueberry jam recipe gets a subtle, earthy twist from a few fresh thyme sprigs. A perfect way to use those fresh summer blueberries! No pectin required.
This crockpot blueberry jam is a summertime essential, and it's absurdly easy: Just throw everything together in a slow cooker and let it bubble away. This low-and-slow method gives you a rich, sweet, concentrated slow cooker jam that's perfect on your morning toast, bagels, homemade biscuits, crostini, and more!
Blueberries are the star of the show here, but we're also adding a few sprigs of fresh thyme for a mellow, earthy twist that gives this jam a bit of extra depth and flavor. Serve it fresh or make a big batch for freezer jam you can use all year long.
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Ingredients
This recipe is pretty straightforward, but we have a few notes before you get started:
- We love using fresh blueberries in this recipe, but you can use frozen blueberries instead if that's what you have! Note: If you use frozen berries, you may need to extend the cook time by an hour or two in order for the jam to thicken enough.
- Fresh lemon juice brings a nice balance to this jam and cuts through the sweetness a bit. You can also add some fresh lemon zest if you like! Its effect is pretty subtle: If you don't have lemon on hand, feel free to skip it!
- Granulated Sugar sweetens this jam, but more importantly, the sugar helps create the jam's thick, glossy, syrup-y texture. (For a deeper, richer flavor, you can use brown sugar instead of white sugar!)
- Fresh thyme sprigs give this jam some depth and complexity. The flavor is pretty mellow: You can use more or less thyme to adjust the intensity! We'll keep the thyme sprigs whole, so that they're easy to pull out once the berries are cooked.
- A pinch of kosher salt adds balance and makes our flavors "pop"!
Riffs and Substitutions
This crockpot jam recipe is very forgiving, and it's easy to customize with whatever you have on hand! Some of our favorite variations:
- Swap the thyme for fresh basil (à la our strawberry basil jam!) You can also omit the herbs entirely for a regular blueberry jam.
- Add a splash of whiskey or rum when you mix everything together for an extra punch of flavor!
- No blueberries? Use strawberries, blackberries, or raspberries instead (or use a combo of a few different things to make a mixed berry jam!) You can also add a diced apple, pear, or peach to this jam for fun flavor mixes!
- Adjust the amount of sugar. You can reduce the sugar by up to 50% without changing the texture and flavor of this jam too much. You can also swap the processed sugar for maple syrup or honey if you'd like, but the jam will need to cook longer to thicken properly.
How to Make This Jam
Cook the Blueberries
Start by adding everything to the bowl of a slow cooker (Image 1, below) and stir it all together (Image 2). Leave the thyme sprigs whole (we'll pull them out after the blueberries cook down a bit!)
Cover the crockpot and cook the berries on low for about 6 hours, until they're soft and have darkened in color. The blueberries will hold their shape pretty well, but they'll be soft, wrinkled, and floating in a pool of dark, purple-y syrup (Image 3, below).
Remove the Thyme
Use a pair of tongs to remove the thyme sprigs from the berries (Image 4, above). They've already infused our jam with plenty of flavor, and our final jam will be much smoother without those herbs.
Immersion Blend to Smooth the Jam
Grab an immersion blender and carefully pulse the berries a few times to break up any large pieces (Image 5, above).
Blend the berries as much (or as little!) as you like: You can pulse the blender just a few times for a chunky, rustic jam, or run it longer for a smoother, more spreadable puree consistency.
Pro Tip: Depending on the size of your crock pot, you may need to tip the bowl to the side to concentrate the blueberries in one area, so that the head of the immersion blender can be fully submerged in the jam (it will splatter less this way!) We used a 5-quart Crock-Pot in these photos, and blending was easiest if we tipped the pot to one side. Always use caution when blending hot liquids.
Thicken the Jam
Once blended, the jam may be a bit on the runny side. To thicken it up, let continue cooking on low - UNCOVERED - for another 1-3 hours (give it a stir every 30 minutes or so to check its progress!)
After a few hours of uncovered cooking, the jam will be thicker and will deepen in color (Image 6, below).
Let the jam continue to cook, uncovered, until it reaches your desired consistency. Keep in mind that the jam will continue to thicken as it cools (similar to our slow cooker apple butter!)
Storing and Freezing Jam
Once your homemade blueberry jam has thickened, let it cool completely, then transfer it to airtight containers with tight-fitting lids (we love these 4-ounce Ball Jars!) Store jam in the refrigerator for up to a week, or freeze it for up to 6 months. Defrost frozen jam in the fridge overnight, then use normally.
Choosing the Right Slow Cooker
Because this recipe makes a fairly small batch of jam, a smaller slow cooker works best here! We used a 5-quart Crock Pot in these photos; this jam also works well in 3-quart slow cookers.
Larger slow cookers can dry the blueberries out more quickly in this recipe, and they also make it more difficult to use an immersion blender without splattering. If your slow cooker is larger than 5 quarts, we recommend doubling this recipe for best results!
Serving Suggestions
Homemade jam is super versatile! A few of our favorite ways to use it:
- As a spread on toast, bagels, scones (this jam + our lemon poppyseed scones = *chef's kiss*).
- Add a dollop to oatmeal, yogurt, pancakes, or waffles at brunch!
- Use it as a glaze on roasted pork, chicken, or salmon.
- On top of a slice of your favorite cheesecake or a scoop of ice cream.
- As a filling for cakes, cupcakes (add a layer of jam between layers of white chocolate cake, or pipe it into the center of your lemon vanilla cupcakes!) or thumbprint jam cookies!
FAQs
No - this jam has not been pH-tested for safe home canning. If you'd like to save this jam for later, we recommend freezing it!
Yes! Just combine all ingredients in a medium saucepan and cook over low heat, stirring occasionally, for 30-45 minutes until blueberries are very soft. Turn off the heat, remove the thyme, and let cool at least 15 minutes before blending with an immersion blender. Return saucepan to the stove over low heat and let the jam thicken until it reaches your preferred consistency.
We prefer using an immersion blender to smooth out this jam, but you could also give the blueberries a light mash with a potato masher OR pulse cooled jam a few times in a blender or food processor to work through any chunks. You can also leave the jam chunky if you prefer!
Dried thyme can make this jam a little bit too earthy and intense, so we recommend sticking to fresh thyme here. Fresh herbs lend a fairly delicate flavor that doesn't quite translate when you make this jam with dried herbs. If you don't have fresh thyme, you can use a few fresh basil leaves or just leave the herbs out entirely!
We have NOT tested this recipe in an Instant Pot or other pressure cooker. Because pressure cookers typically require a fair amount of liquid to properly come to pressure, this recipe would likely not be a great candidate for Instant Pot pressure cooking. We recommend making this recipe in a slow cooker as written, or making it in a saucepan on the stovetop!
This is a fairly small batch blueberry jam recipe: It yields about 1 ½ to 2 cups of jam. Want a bigger batch? You can easily double or triple the recipe using the handy 2x and 3x buttons in the recipe card below!
We love serving a bowl of this blueberry jam on an easy cheese and charcuterie board: It's excellent alongside tangy goat cheese or creamy brie cheese! This jam is also excellent on a toasted bagel with a bit of cream cheese.
More Summer Berry Recipes
Did you make this recipe? Leave a comment and star rating below to let us know how it turned out!
Print📖 Recipe
Slow Cooker Blueberry Jam
- Prep Time: 5 minutes
- Cook Time: 8 hours
- Total Time: 8 hours 5 minutes
- Yield: Makes 1 ½ to 2 cups 1x
- Category: Sauce
- Cuisine: American
- Diet: Vegan
Description
This easy blueberry jam is made entirely in the slow cooker, and it gets some extra depth and complexity thanks to a few fresh thyme sprigs.
Ingredients
- 1 pound fresh blueberries (about 4 cups)
- 1 Tablespoon lemon juice
- 6 sprigs fresh thyme
- ⅔ cup sugar
- pinch of kosher salt
Instructions
Cook the Blueberries (6 hours)
- Stir blueberries, lemon juice, thyme sprigs, sugar, and a pinch of salt together in the bowl of a slow cooker. Cover and cook on low for 6 hours, until berries are soft, wrinkled, and surrounded by a pool of deep purple syrup.
- Turn off the heat and let berries cool for 10-15 minutes. Use kitchen tongs to remove the thyme sprigs (discard or compost them).
Blend for a Smoother Consistency (5 minutes)
- Use an immersion blender to carefully pulse the berries a few times, until you have a smooth jam. Note: Depending on the size of your slow cooker, you may need to tilt it to one side in order to fully submerge the head of the immersion blender in the mixture to avoid splattering. Always use caution when blending warm liquids.
Thicken the Jam (1-3 hours)
- Turn the heat back to low and continue to cook the jam - UNCOVERED - for an additional 1-3 hours until jam has thickened to your desired consistency. (Don't worry if it still looks a little bit loose - the jam will continue to thicken as it cools!)
- Serve jam warm or let it cool completely and transfer to an airtight container. Store in the fridge for up to a week, or the freezer for up to 6 months.
Notes
Additions and Substitutions. Use different berries (strawberries, blackberries, raspberries) if you like. Add 2 Tablespoons bourbon or rum for extra flavor. Use basil instead of thyme, or omit the herbs entirely for a plain blueberry jam. Use maple syrup or honey in place of sugar (you may need to cook the jam a bit longer so it thickens properly). You can also reduce the sugar by up to 50% if you prefer less sweetness. Use frozen blueberries instead of fresh (you may need to let the jam cook longer to thicken properly).
Storing and Freezing. Let jam cool completely, then transfer to an airtight container (we like using small mason jars or another freezer-safe container). Refrigerate jam for up to a week or freeze for up to 6 months. Defrost frozen jam in the fridge overnight. This recipe has NOT been pH-tested for safe home canning: If you would like to store jam for an extended period of time, we recommend freezing it.
What size slow cooker should I use? This jam works best in smaller slow cookers (2-5 quarts). We used a 5-quart Crock Pot in these photos. If you have a larger slow cooker, we recommend doubling the recipe (the berries will cook more evenly, and the jam will be easier to blend).
Nutrition
- Serving Size: 2 Tablespoons
- Calories: 65
- Sugar: 14.9 g
- Sodium: 103.9 mg
- Fat: 0.1 g
- Carbohydrates: 16.8 g
- Protein: 0.3 g
- Cholesterol: 0 mg
Keywords: sauce, slow cooker, crockpot
C
Tried this recipe tonight using frozen blueberries. I found it to be extremely runny after 5 hours in the slow cooker. I would cut the amount from 4C to 3C as frozen berries produce more liquids. Other than that it smells and tastes wonderful! Thank you for sharing your recipe.
★★★★★
Team Life As A Strawberry
You're exactly right that frozen blueberries have a higher liquid content. We're so happy you enjoyed it!
Sue
Has anyone tried with frozen blueberries? Any changes to make to recipe if frozen used?
Jessie
You can totally use frozen blueberries here! You may just need to extend the cooking time a little bit if it looks too thin.
Desi
can this recipe be canned as well as refrigerated?
Jessie
This recipe has not been tested for canning but I often keep it in small jars in the freezer to save it throughout the year!
Sarah
can this be frozen or canned?
Jessie
Definitely! I always freeze a container or two of this when I make it in the summer so we can use it all year long - it holds up really well in the freezer. I'm not a canning expert, so if you decide to can, just follow proper canning procedures.
Ms. Ruth
what size slow cooker? Thanks.
Jessie
My slow cooker is on the smaller side, maybe 3 or 4 quarts? You can use any size you like, though - the blueberries release quite a bit of liquid. If your slow cooker is especially large, you may just want to keep an eye on it and adjust the cooking time or add a splash of water if you notice the jam starts to get too thick. This recipe is very forgiving, so use what you have on hand!