Low-Sugar Strawberry Jam

Strawberry jam, fresh strawberries

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Prep: 25 mins
Cook: 15 mins
Canning Time: 10 mins
Total: 50 mins

This easy recipe for strawberry jam uses less than half the sugar called for in traditional recipes. The result is a healthier treat that boasts the full natural flavor and vibrant color of the fruit.

The recipe calls for low-methoxyl pectin (made from citrus peels) and calcium powder, both of which are available from brands such as Pomona's Universal Pectin. The combination of low-methoxyl pectin and calcium makes it possible to get a good gel even when using little or no sugar.

In low-sugar recipes it is especially important to use fully ripe, flavorful fruit. However, it doesn't matter whether the strawberries are fresh or frozen, as long as they were picked at their seasonal best.


  • 2 pounds strawberries (frozen or fresh, green hulls removed)
  • 1/2 teaspoon calcium powder
  • 4 ounces water
  • 2 teaspoons citrus pectin powder (low methoxyl)
  • 1/4 to 1 cup sugar

Steps to Make It

  1. Put the strawberries in a large, non-reactive pot (no aluminum or non-enameled cast iron). If you are using frozen berries, let them thaw at room temperature before proceeding with the recipe.

  2. Mash the strawberries with a potato masher.

  3. In a measuring cup, make calcium water by stirring the calcium powder into the water. (You will only be using a small amount of this mixture in the recipe.)

  4. Add 2 teaspoons of the calcium water to the strawberries and stir well.

  5. In a separate bowl, mix 2 teaspoons of the pectin powder with the sugar. Start with the smallest amount of sugar and taste for sweetness; add more if needed, not exceeding 1 cup.

  6. Bring the fruit and calcium water to a boil over high heat. Add the sugar and pectin mixture and stir constantly for 1 to 2 minutes until the pectin and sugar completely dissolve.

  7. Allow the jam to return to a full boil. Turn off the heat.

  8. Ladle the hot jam into clean canning jars (it is not necessary to sterilize the jars for this recipe), leaving 1/2-inch of headspace. Fasten canning lids. Process in a boiling water bath for 10 minutes.

Recipe Tips

Once processed and sealed, the jam will keep, unopened, for 1 year. Once opened (or if unsealed), low sugar strawberry jam should be stored in the refrigerator where it will keep for 3 to 4 weeks.

You can store the remainder of the calcium water in a clearly labeled jar in the refrigerator for several months. Use it in future batches of low-sugar preserves; shake before using. Discard it if the calcium powder that settles to the bottom discolors or you see any signs of mold.

Recipe Variation

Use 1/4 to 1/2 cup honey instead of the sugar. Although honey doesn't combine with pectin and acidity in the same way sugar does to create a gel, it will work in a recipe that uses the combination of calcium and low-methoxyl pectin powder.