Blueberry Jam (Low Sugar)

12 servings Prep: 15 m Cook: 15 m Total: 30 m Intermediate
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Blueberry Jam (Low Sugar)
It is Blueberry Season and everyone loves blueberries also known as star berries. We love them fresh picked, eaten straight from the bush, baked into a favorite dessert, or enjoyed as jam, preserves and jelly. This low-sugar blueberry jam uses fresh berries, lemon juice, and pectin for a bright, naturally sweet spread perfect for biscuits, toast, or thumbprint cookies. Maine is the blueberry production capital of North America but they are grown in almost all states. Blueberries will not ripen any more once they have been picked off the bush. Gently shake the bush and the ripened berries fall—much easier than picking one berry at a time.

Ingredients

12 servings
  • 10 cups fresh blueberries
  • 4 1/2 cups sugar
  • 4 tablespoons lemon juice
  • 1 1/2 packages fruit pectin (1.75 ounce packages)
  • 1/4 cup water

Step-by-Step Instructions

  1. Combine the berries, water, lemon juice, sugar and one box of the pectin in a 4 quart pot. You have the option of squashing the berries in the pot or pureeing the berries in a food processor prior to mixing with other ingredients.
  2. Bring the ingredients to a full boil over medium-high heat, stirring constantly to prevent sticking.
  3. Once it reaches a full rolling boil that cannot be stirred down, add the remaining 1/2 package of pectin. Bring it back to a boil for another 3 to 4 minutes, stirring constantly.
  4. After a slight cooling, the mixture should coat the back of a metal spoon. Fill your sterilized jars leaving 1/4 inch headspace, wipe rims clean, and process in a boiling water bath for 10 minutes. Jam will thicken upon cooling.

Common Problems and Solutions

Q: Why didn't my jam set properly?

A: Make sure you reach a full rolling boil that cannot be stirred down before adding the second portion of pectin. The jam will continue to thicken as it cools, so don't judge consistency while hot. If it's still too thin after 24 hours, you can re-cook it with additional pectin.

Q: Can I use frozen blueberries instead of fresh?

A: Yes, but thaw them completely and drain excess liquid first. Frozen berries release more water, which can affect the jam's consistency. You may need slightly less water in the recipe.

Q: How do I know when the jam is done cooking?

A: Use the spoon test—dip a cold metal spoon into the jam, lift it out, and turn it sideways. When the jam runs off in a sheet rather than individual drops, it's ready. The mixture should coat the back of the spoon.

Tips and Techniques

Slightly under-ripe berries have more natural pectin than fully ripe ones, so include a few lighter-colored berries in your mix for better setting. Stir constantly during boiling to prevent scorching on the bottom of the pot. Have your jars sterilized and ready before you start cooking so you can fill them while the jam is still hot.

Ingredient Substitutions

  • fresh blueberries: frozen blueberries
  • lemon juice: bottled lemon juice
  • sugar: low-sugar pectin designed for reduced sugar recipes

Equipment Needed

  • 4-quart heavy-bottomed pot or Dutch oven
  • Metal spoon for testing consistency
  • Food processor (optional, for pureeing berries)
  • 12 half-pint canning jars with lids and bands
  • Large pot for water bath canning
  • Jar lifter
  • Canning funnel
  • Clean cloth for wiping jar rims

Historical Context

Water bath canning became popular in the American South during the late 1800s and early 1900s as a way to preserve summer’s bounty for winter enjoyment. Low-sugar jam recipes became widespread after pectin products became commercially available in the 1920s, allowing home canners to make preserves with less sugar than traditional methods required.