Homemade Blueberry Jam

 

Prep Time: 20 minutes

Cook Time: 30 minutes

Process Time: 10 minutes

Total Time: 1 hour (plus cooling)

Intensity Level: Moderate (Requires attention during the boiling and canning phases)

Ingredients
6 cups (about 2 lbs / 900g) fresh blueberries (or frozen, do not thaw)

2 cups (400g) granulated sugar

¼ cup (60ml) fresh lemon juice (about 1-2 lemons)

1 tablespoon lemon zest (optional, for extra brightness)

1 pouch (3 oz / 85ml) liquid fruit pectin

½ teaspoon unsalted butter (optional, helps reduce foaming)

Equipment
Large, heavy-bottomed pot (at least 6-quarts)

Wooden spoon or heatproof spatula

Potato masher or fork

Fine-mesh sieve (optional)

4-5 sterilized half-pint canning jars, lids, and bands

Water bath canner or a very large, deep pot with a rack

Jar lifter and canning funnel

Ladle

Clean kitchen towels

Small plate (for testing the set)

Instructions
Part 1: Preparation (Intensity: Low)
Sterilize Your Jars: Begin by washing your jars, lids, and bands in hot, soapy water. Rinse them thoroughly. Keep the jars hot by placing them in your water bath canner filled with water and bringing it to a simmer. Keep the lids and bands in a separate small pot of hot (not boiling) water until ready to use. This step is essential for safe canning and ensures a proper seal.

Prepare the Blueberries: Rinse the blueberries under cold water and discard any stems, leaves, or mushy berries. If you are using frozen blueberries, there is no need to thaw them; simply measure them frozen. Place the berries in a large bowl.

Mash the Berries: Using a potato masher or a sturdy fork, gently crush the blueberries. You want to break them down enough to release their juices, but still leave some whole berries for texture. If you prefer a smoother jam, you can pulse them a few times in a food processor, but be careful not to puree them completely. A good jam should have some texture.

Measure and Prep Other Ingredients: Measure out your sugar, lemon juice, and lemon zest. Having everything ready before you start cooking will make the process much smoother. Place your small plate in the freezer; you will use this later to test the set of your jam.

Part 2: Cooking the Jam (Intensity: Moderate)
Combine Base Ingredients: In your large, heavy-bottomed pot, combine the mashed blueberries, lemon juice, and lemon zest (if using). Stir to combine. If you are using the optional butter, add it now; it will help minimize the foam that forms during boiling.

Heat the Mixture: Place the pot over medium heat and bring the blueberry mixture to a simmer. Cook for about 5-7 minutes, stirring occasionally, until the berries have softened further and released more of their juices. The mixture should be hot and bubbling gently.

Add the Sugar: Stir in the granulated sugar all at once. Continue to stir constantly over medium heat until the sugar has completely dissolved. You will know the sugar is dissolved when the mixture no longer feels gritty on the bottom of the pot and it begins to look glossy.

The Rolling Boil: Once the sugar is fully dissolved, increase the heat to medium-high and bring the mixture to a full, rolling boil. A rolling boil is one that cannot be stirred down. Once reached, boil the mixture for exactly 5 minutes, stirring constantly. Intensity Note: This is the most demanding part of the recipe. You must remain attentive and keep stirring to prevent the sugars from scorching on the bottom of the pot. The mixture will bubble vigorously and may splatter, so be careful.

Add the Pectin: After the 5-minute boil, quickly stir in the entire pouch of liquid pectin. Return the mixture to a full, rolling boil and boil for exactly 1 minute more, stirring constantly. You will notice the jam begin to thicken and take on a glossy, jewel-like appearance.

Skim and Finish: Remove the pot from the heat. Using a metal spoon, skim off any foam that has risen to the surface. This ensures a clear, beautiful jam. Discard the foam or save it in a small dish for a cook’s treat.

Test the Set: Retrieve your chilled plate from the freezer. Place a small spoonful of jam on the plate and return it to the freezer for 1-2 minutes. Remove the plate and push the edge of the jam with your finger. If it wrinkles slightly and holds its shape, it is ready. If it is still runny, you can return the pot to the heat and boil for another 1-2 minutes, then test again. Be careful not to overcook, as the jam will continue to set as it cools.

Part 3: Canning and Processing (Intensity: Moderate-High)
Fill the Jars: Place your sterilized jars on a clean kitchen towel. Using a ladle and a canning funnel, carefully fill each hot jar with the jam, leaving ¼-inch of headspace at the top. Intensity Note: The jam is extremely hot and sticky. Handle with care to avoid burns. Wipe the rim of each jar with a clean, damp cloth to remove any sticky residue; this is crucial for achieving a proper seal.

Remove Air Bubbles: Gently slide a clean plastic spatula or a bubble popper tool around the inside of the jar to release any trapped air bubbles. Add more jam if needed to maintain the ¼-inch headspace.

Seal the Jars: Place a lid on each jar and screw on the band until it is fingertip-tight. Do not overtighten, as this can prevent air from escaping during processing and interfere with the seal.

Water Bath Processing: Using your jar lifter, carefully lower the filled jars into the boiling water of your water bath canner, ensuring they are covered by at least 1-2 inches of water. Bring the water back to a full boil, cover the canner, and process for 10 minutes. Adjust for altitude if necessary: add 5 minutes for every 1,000 feet above sea level.

Cool and Check Seals: After processing, turn off the heat and let the jars sit in the hot water for 5 minutes. Then, use the jar lifter to remove the jars and place them on a towel-lined counter to cool completely, undisturbed, for 12-24 hours.

Final Check: Once cooled, press the center of each lid. If it is firm and does not pop up, the jar is sealed. Remove the bands, wipe the jars clean, and label them. Sealed jars can be stored in a cool, dark place for up to a year. Any unsealed jars should be refrigerated and used within 3 weeks.

Serving & Storage: Serve this Homemade Blueberry Jam on toast, English muffins, or buttermilk biscuits. It is also delicious swirled into oatmeal or yogurt, spread between layers of a cake, or used as a topping for pancakes and waffles. For a savory twist, try it as a glaze for roasted chicken or pork.

Nutrition Information
Nutrition information is an estimate and will vary based on exact ingredients and serving size.

Serving Size: 1 tablespoon (approx. 20g)

Calories: 45

Total Fat: 0g (0% DV)

Saturated Fat: 0g (0% DV)

Trans Fat: 0g

Cholesterol: 0mg (0% DV)

Sodium: 0mg (0% DV)

Total Carbohydrates: 12g (4% DV)

Dietary Fiber: 0g (0% DV)

Total Sugars: 11g

Includes 11g Added Sugars (22% DV)

Protein: 0g

Vitamin D: 0mcg (0% DV)

Calcium: 0mg (0% DV)

Iron: 0mg (0% DV)

Potassium: 0mg (0% DV)