Blueberry Jam

4.37 from 76 votes

Easy homemade blueberry jam made without added pectin. This small batch recipe sets on the natural pectin in the berries plus a splash of lemon juice, with simple water bath canning instructions.

Cook Time20

Canning Time (optional)10

Total Time30

Course: Jam

Cuisine: American

Servings: servings, makes about 3 to 4 half pint (8 oz) jars

Author: Ashley Adamant

Equipment

Water Bath Canner
Canning Funnel
Canning Jars, Lids, and Rings

Ingredients

4 cups blueberries fresh or frozen
2 cups sugar
1/4 cup lemon juice fresh or bottled

US Customary - Metric

Instructions

Place blueberries and lemon juice in a heavy-bottomed jam pot and gently bring to a simmer over low heat. Mash the blueberries to help them release their juices.
Once the blueberries have released their juices, increase heat to medium-high, and add sugar.
Cook the jam until it reaches gel stage, about 20 minutes. Test for gelling on a plate that's been in the freezer, or use an instant-read thermometer (220 degrees F at sea level).
Pour finished jam into prepared jars, seal with 2 part lids. Store in the refrigerator or water bath can for a shelf-stable blueberry jam.

Canning Instructions (Optional)

To can the blueberry jam, fill clean canning jars leaving 1/4 inch headspace. Seal with 2 part lids and process in a water bath canner for 10 minutes. Turn off heat and allow the jars to set in the canner for an additional 5 minutes (prevents siphoning) before removing them to cool on a towel on the counter.
Check seals after 24 hours and store any unsealed jars in the refrigerator for immediate use. Sealed jars should maintain quality in the pantry for 12-18 months.

Notes

Yield: This small batch recipe makes about 3 half-pint (8 oz) jars. Exact yield depends on how far you cook it down. With a softer set, you'll end up closer to 4 half-pints.

Batch Size: You can scale this recipe up to about 8 cups of berries, and it still cooks evenly. For more than that, make separate batches back to back rather than one oversized pot, which won't set reliably.

Low Sugar Blueberry Jam: You can cut the sugar to 1 cup for a less sweet jam. Expect a longer cook time and a slightly lower yield, since sugar helps the jam set and concentrate.

Using Pectin: For a firmer, faster set, use a box of standard powdered pectin (Sure-Jell or Ball Classic) and follow the box directions, which call for more sugar. For a low-sugar set, use low-sugar pectin or Pomona's Universal Pectin. Avoid liquid pectin here.

Lemon Juice: Blueberries are acidic enough to water bath can without lemon juice. It's added for flavor and to boost the natural pectin for a better set. Fresh or bottled both work.

Frozen Berries: Frozen blueberries work just as well as fresh, with no need to thaw first.

Storage: Refrigerator jam keeps 3 to 4 weeks. Freezer jam lasts up to 6 months. Water bath canned jars keep 12 to 18 months in a cool, dark pantry. Refrigerate after opening.

Altitude Adjustments: Process for 10 minutes at elevations below 6,000 feet, or 15 minutes above 6,000 feet.

Nutrition