Blueberry Jam

Preserve the best of summer's bounty to enjoy all year long with this easy Blueberry Jam recipe! The homemade jam is perfect on toast, stirred into yogurt, spooned over ice cream, dolloped on pancakes, or shared with friends over the holidays.

I've been making this homemade blueberry jam recipe for years, because the same thing happens each season: I take the kids to a nearby farm to pick blueberries for a couple of hours, and we inevitably come home with more fresh fruit than we can possibly eat at once. When this happened again last week, I turned to my favorite recipe as a simple way to preserve our harvest. After all, we can only consume so many batches of Blueberry Muffins or Blueberry Scones in one week!

How to make Blueberry Jam from Scratch:

This recipe is incredibly simple -- it's just important to get all of your ingredients and equipment prepared in advance because the process moves quickly. In less than 45 minutes, you can have an entire batch (12 jars!) of homemade blueberry jam canned and ready for the pantry. There's nothing more satisfying than hearing that "pop" as the lids seal!

Ingredients for Blueberry Jam:

• Blueberries
• Lemon juice
• Granulated sugar
• Butter
• Powdered fruit pectin

Equipment Needed:

As I mentioned above, you need to have all of your ingredients and supplies ready to go before you get started, since this process goes very quickly.

• 12 sterilized half-pint mason jars and lids: this recipe yields about 11-12 cups of jam, so you can use any size jars that you prefer (or a combination) to accommodate this amount. I like the half-pint jars because it's just the right amount of jam to keep in the fridge after it's opened.
• A sterilized funnel: this makes it easier to get the jam inside the jar without spilling; however, it’s fine if you don’t have a funnel — you can carefully spoon the jam into the jars instead.
• Tongs: these canning tongs are incredibly helpful when taking the jars in and out of the boiling water
• Saucepan: for cooking the berries. Allow plenty of room for the berries to boil, bubble and foam!
• Canner or Large Pot for Boiling Jars: this needs to be very deep so that you can cover the jars with at least 1-2 inches of water. I use my deepest stock pot for this step, since I don't have an official canner to process the jars.
• Mixing bowl
• Potato masher or food processor: to smash the berries before cooking
• Wooden spoon

How to Sterilize Jars and Lids for Jam:

It’s a good practice to sterilize the jars and lids before canning in order to kill any bacteria, fungi or yeasts before filling. There are a variety of ways to sterilize the jars (here’s a helpful article with different options). I typically use the dishwasher, and make sure that the jars and lids stay hot in the machine until I'm ready to fill them.

Step 1: Crush the Blueberries

I use a potato masher to squish my berries, but you can also pulse a few times in a food processor if that's easier. Just don't puree the fruit -- you want some texture to the berries since they will continue to cook down on the stovetop.

Step 2: Combine Blueberries, Lemon Juice, Butter and Pectin

Place the crushed blueberries, lemon juice, butter and pectin in a large Dutch oven or saucepan.

Step 3: Boil

Bring the blueberry mixture to full rolling boil, stirring constantly.

Step 4: Add Sugar

As soon as the mixture boils, stir in the sugar. Return to a full rolling boil and boil exactly 1 minute, stirring constantly.

Step 5: Fill Jars

Remove the berries from the heat, skim off the foam, and quickly ladle the jam into hot jars. Add the lids and rings.

Step 6: Process Jars in Boiling Water

Set the hot jars on a rack in a canner or in a large pot of boiling water. Boil for 10 minutes.

Step 7: Cool

Place the jars on a towel or rack to cool overnight.

How to Serve Blueberry Jam:

This homemade blueberry jam is delicious spread on toast, dolloped on biscuits or cornbread, spooned over pancakes or waffles, stirred into yogurt or oatmeal, or drizzled over ice cream.

The jam is also a great gift to share with friends, neighbors and family at the holidays. I love to pull a jar out of the pantry, tie a nice ribbon around the lid, and gift it to someone in December. I don't have to fuss with baking or shopping during the busy season, and it's nice to enjoy a taste of summer during the cold, gray months.

Preparation and Storage Tips:

• Make sure that you leave about ¼-inch of headspace in each jar. Leaving the proper amount of headspace in a jar is important to ensure a vacuum seal. If there's too little headspace, the jam may expand and bubble out when air is being forced out from under the lid during processing.
• The jam will not set immediately, so it’s important to allow the jars to rest without interruption at room temperature until cool (or overnight).
• How to Store Blueberry Jam: Once the jam has had a chance to cool, you can check the seals. The lids should be down in the center or stay down when pressed. Unsealed jars should be refrigerated and used within 3 weeks. Properly sealed and processed jars of blueberry jam should be stored in a cool, dark, dry place (such as a pantry). The homemade blueberry jam will last for up to 1 year.
• Can you freeze blueberry jam? I do not recommend freezing this homemade jam. If you want to prepare blueberry freezer jam, you need to follow a recipe that is specifically designed for the freezer jam method.

How to Thicken Blueberry Jam:

Most recipes for blueberry jam call for 2 boxes (or 3.5 ounces) of powdered fruit pectin. Over our many jam-making years, my mom has taught me to always err on the side of more pectin than recommended to ensure that the jam actually thickens. There’s just nothing more disappointing than runny blueberry jam!

That’s why I weigh out 4 ounces of powdered fruit pectin for each batch, which is equivalent to about ¾ cup of pectin (or slightly more than two boxes). I buy the pectin in bulk at a local country market, and then I don’t have to worry about partially-used boxes. Using a full 4 ounces of pectin results in a perfectly thick blueberry jam every time. Mom always knows best…

Why is my blueberry jam runny?

If your jam didn't set, this could be the result of a number of different issues. Let's troubleshoot!

• It can take 24-48 hours for a batch of jam to finish setting up. This thought goes through my mind every summer when I'm filling the jars and the jam looks thinner than I'd expect! I have to remind myself that it will not be thin once it cools and sets -- patience is key.
• Overcooked Pectin: It's important to boil the jam with the sugar for exactly 1 minute. If you overcook the pectin, it may break down and fail to gel.
• Reduced Sugar: I know that 8 cups sounds like a lot of sugar, but trust me: you need all of it! Stick with regular granulated sugar (instead of sugar substitutes like Splenda or stevia) and do not decrease the quantity called for in the recipe. Jam making is an exact science, so measuring the correct quantities of fruit, sugar and pectin are essential to a successful batch of jam.
• Doubled or Halved the Recipe: Since jam-making is an exact science (as noted above), many experts suggest that you should not try to double the recipe to make a larger batch or cut the ingredients in half to make a smaller batch. If you adjust the recipe in any way, the jam may not set properly.

If all else fails and your jam doesn't set, don't stress! Just re-name is "blueberry sauce," and serve it with yogurt, ice cream, oatmeal, pancakes and waffles. It will still be delicious!

Why Add Lemon Juice to Jam:

You won’t actually taste the lemon in the jam. Instead, the lemon juice serves a very specific purpose. The lemon juice lowers the pH of the jam, which neutralizes negative charges on the strands of pectin and helps your jam set. Again, no runny jam!

Why Add Butter to Jam:

The butter is the only ingredient that is optional in this recipe (although I highly recommend including it). You can't taste the butter in the final product; however, the butter serves a specific purpose. As you heat the berries, the proteins open up into strands that get tangled up and help stabilize the bubbles into a foam. Adding the butter (a fat) helps to prevent this tangling, and therefore reduces the amount of foam on top of your jam.

Do blueberries need pectin?

Pectin is a natural fiber found in plant cell walls, and most concentrated in the skin of fruits. It is water-soluble and binds with sugar and fruit acid to form a gel. The pectin is a necessary ingredient in this recipe, as it helps the jam set properly. The pectin also shortens the cooking time, resulting in a fresher blueberry flavor.

Is blueberry jam good for you?

As you can see from the list of ingredients, there is a lot of sugar in any jam recipe and therefore this treat should be enjoyed in moderation. Blueberry jam is a deep purple color, thanks to all of the antioxidants, vitamins and flavonoids in blueberries! While it may be healthier to eat the blueberries on their own, at least you know you're getting some additional benefits when you slather that beautiful homemade jam on top of your morning toast!

Can I use frozen blueberries to make this jam?

I only recommend using fresh, ripe blueberries for this recipe. They will have the best acidity and tannins to give the jam a more complex flavor, and the skins will be the proper texture. Frozen blueberries tend to be mushier and more watery than fresh fruit when thawed, which will likely alter the consistency of your jam.

More ways to enjoy fresh blueberries at home:

• Easy Blueberry Muffins
• Blueberry Scones
• Banana Blueberry Smoothie
• Blueberry Bread
• Whole Wheat Banana Blueberry Muffins
• Blueberry Buckle

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Blueberry Jam

This easy homemade Blueberry Jam recipe is the perfect way to preserve fresh summer fruit!

Course condiment

Cuisine American

Keyword blueberry jam recipe, homemade blueberry jam

Prep Time 20 minutes

Cook Time 20 minutes

Resting Time 12 hours

Total Time 12 hours 40 minutes

Servings 12 cups (approximately, may be slightly less)

Calories 38kcal

Author Blair Lonergan

Ingredients

• 4 cups crushed blueberries (8 cups of whole fresh blueberries before crushing)
• 2 tablespoons freshly-squeezed lemon juice
• 1 teaspoon butter
• 4 ounces (about ¾ cup) powdered fruit pectin
• 8 cups granulated sugar

Instructions

• Prepare home canning jars and lids according to manufacturer’s instructions for sterilized jars. Keep jars hot until filled. Always use new lids.
• Place berries, lemon juice, butter and pectin in a large pot. Bring mixture to full rolling boil, stirring constantly. Stir in sugar. Return to a full rolling boil and boil exactly 1 min., stirring constantly.
• Remove from heat and skim off foam. Quickly ladle into the hot jars, leaving ¼-inch of head space at the top. Use a damp cloth to wipe any drips from the top and sides of the jars. Cover with hot lids and tighten rings firmly.
• Set the hot jars on a rack in a canner or in a large pot of boiling water. The water needs to cover the jars by at least 1-2 inches. Boil the jars for 10 minutes.
• Remove the jars from the boiling water and set on a towel or rack to cool overnight (but not more than 24 hours).
• When cool, check the seals. The lids should be down in the center or stay down when pressed. Store in a cool, dark, dry place. Unsealed jars should be refrigerated and used within 3 weeks.

Notes

• Make sure that you leave about ¼-inch of headspace in each jar. Leaving the proper amount of headspace in a jar is important to ensure a vacuum seal. If there's too little headspace, the jam may expand and bubble out when air is being forced out from under the lid during processing.
• The jam will not set immediately, so it’s important to allow the jars to rest without interruption at room temperature until cool (or overnight).
• How to Store Blueberry Jam: Once the jam has had a chance to cool, you can check the seals. The lids should be down in the center or stay down when pressed. Unsealed jars should be refrigerated and used within 3 weeks. Properly sealed and processed jars of blueberry jam should be stored in a cool, dark, dry place (such as a pantry). The homemade blueberry jam will last for up to 1 year.
• Can you freeze blueberry jam? I do not recommend freezing this homemade jam. If you want to prepare blueberry freezer jam, you need to follow a recipe that is specifically designed for the freezer jam method.

Nutrition

Serving: 1tablespoon | Calories: 38kcal | Carbohydrates: 10g | Protein: 1g | Fat: 1g | Saturated Fat: 1g | Cholesterol: 1mg | Sodium: 2mg | Potassium: 5mg | Fiber: 1g | Sugar: 9g | Vitamin A: 4IU | Vitamin C: 1mg | Calcium: 1mg | Iron: 1mg