Ingredients
Fruit and Pectin
- 5 cups blueberries
- 2 boxes pectin (1.75 ounces each)
Sweeteners and Flavorings
- 5 cups sugar
- ⅓ cup lime juice
- 1 tablespoon lime zest
Instructions
- Prepare the Water Bath Canner: Fill a hot water canner about two-thirds full with water and bring it to a rolling boil to prepare for processing the jam jars.
- Combine Blueberries and Pectin: In a large saucepan, mix the blueberries and pectin thoroughly to evenly distribute the pectin throughout the fruit.
- Heat and Add Sugar: Heat the mixture over medium-high heat until it reaches a boil. Stir in the sugar continuously until fully dissolved. Then, add the lime zest and lime juice to the boiling mixture.
- Boil the Jam: Bring the mixture back to a full rolling boil that cannot be stirred down and maintain this boil for 1 minute, stirring constantly to prevent the jam from sticking or burning.
- Remove Foam: Remove the saucepan from heat and skim off any foam that formed on the surface of the jam to ensure a clear final product.
- Perform the Set Test: Spoon a small amount of jam onto a cold plate and let it sit for a minute. If the jam forms a skin and jiggles like firm jelly, it is ready. If not, return to heat and cook slightly longer.
- Fill Prepared Jars: Immediately ladle the hot jam into prepared sterilized jars, filling them to within 1/4 inch of the top. Remove any air bubbles by gently tapping or using a spatula.
- Seal the Jars: Wipe the rims clean to ensure a good seal. For traditional canning jars, place two-piece lids on and screw the bands finger-tight. For Weck jars, place rubber gaskets on the lids, secure lids on jars, and fasten clamps evenly spaced.
- Process in Water Bath: Place the filled jars on an elevated rack in the boiling water bath canner ensuring the water covers jars by at least 2 inches. Cover the canner and process for 10 minutes to safely preserve the jam.
- Cool and Check Seals: Remove jars using jar lifters and set upright on a towel to cool for 12-24 hours. After cooling, check seals by pressing the center of the lids. If a lid springs back, it is not sealed and the jar should be refrigerated. For Weck jars, ensure the seal points downward.
- Store: Remove the rings or clamps once sealing is confirmed. Store the jars in a cool, dark place for up to one year for best quality.
Notes
- Use fresh blueberries for best flavor and color; frozen can be used but may affect texture.
- Ensure jars and lids are sterilized before filling to prevent contamination.
- Do not reduce sugar or pectin amounts as it may affect the jam’s ability to set.
- If the jam does not set after extended cooking, discard or use as a syrup.
- Store opened jars in the refrigerator and consume within 3 weeks.
- Adjust cooking and processing times based on your altitude if above 1,000 feet.
- Prep Time: 15 minutes
- Cook Time: 20 minutes
- Category: Jam, Preserves
- Method: Boiling, Water Bath Canning
- Cuisine: American
- Diet: Vegetarian
Nutrition
- Serving Size: 1 tablespoon (20g)
- Calories: 50
- Sugar: 12g
- Sodium: 0mg
- Fat: 0g
- Saturated Fat: 0g
- Unsaturated Fat: 0g
- Trans Fat: 0g
- Carbohydrates: 13g
- Fiber: 1g
- Protein: 0g
- Cholesterol: 0mg
