iBlueberry Jam

1. If canning, wash 4 half-pint jars, lids, and bands. Place a rack in a deep pot, add jars, and cover with water. Bring to a simmer (180°F) and keep jars hot; prepare lids per manufacturer’s directions.

2. Combine the rinsed and picked over blueberries, granulated sugar, and bottled lemon juice in a wide, heavy pot. Let stand 15 minutes to draw out juices, then lightly mash with a potato masher to your desired texture.

3. Set the pot over medium-high heat and bring to a vigorous boil, stirring frequently to prevent sticking. Maintain a steady boil and cook 15–25 minutes, stirring often and skimming foam as needed, until the jam thickens and reaches 220°F, or a spoonful spread on a chilled plate wrinkles when pushed.

4. Remove from heat and let the jam settle 2 minutes to allow bubbles to subside, then stir to evenly distribute fruit.

5. For refrigerator jam, ladle hot jam into clean jars, leaving 0.25 inch headspace. Wipe rims, apply lids, cool to room temperature, then refrigerate up to 1 month.

6. For canning, remove hot jars from the pot, drain, and ladle hot jam into jars, leaving 0.25 inch headspace. Wipe rims, apply lids and bands fingertip-tight, and return jars to a boiling water bath with at least 1 inch of water above the lids. Bring back to a full rolling boil, then process 10 minutes (add 5 minutes at 1,001–6,000 ft; add 10 minutes above 6,000 ft).

7. Turn off heat, let jars rest in the hot water 5 minutes, then remove to a towel-lined surface. Cool 12–24 hours. Check seals; lids should be concave and not flex. Label and store sealed jars in a cool, dark place up to 1 year; refrigerate any unsealed jars and use within 1 month.