How to Thicken Raspberry Jam With Gelatin

by Fred Decker
Gelatin-based jams are quick, easy and use less sugar.

Gelatin-based jams are quick, easy and use less sugar.

If conventional jam-making isn't working out for you, or if you want to get away from the huge quantities of sugar needed to make ordinary jam set, gelatin might be your best friend. The mysterious balance of raspberries, sugar, acidity and pectin required to make good raspberry jam can be frustratingly difficult to achieve, especially for a tart jam. Unflavored gelatin sets the jam more reliably, and using it enables you to make a jam that's less sweet and has a fresher berry flavor.

Mash the berries lightly and bring them to a gentle simmer. Sprinkling them with up to 1/4 cup of sugar helps bring out their juices more quickly.

Remove 1/2 cup of the berry juice and chill it in your refrigerator until it's cold to the touch. Sprinkle an envelope of unflavored gelatin over the cold juice, and wait for a few minutes until it has absorbed the liquid and softened. Use one envelope of gelatin, or 2 tablespoons, for every quart of berries and juice.

Bring the raspberries to a boil and stir the gelatin mixture. Stir gently for 1 minute, breaking up the raspberries as little as possible, then remove the mixture from the heat.

Stir in half the sugar called for in your original recipe, or the equivalent in agave nectar or artificial sweetener. Taste the jam and add more sweetening if necessary.

Pour the hot jam into sterilized jars, and seal them with fresh, unused lids. Refrigerate the jam immediately.

Items you will need

  • Sugar
  • Unflavored gelatin
  • Agave nectar or artificial sweetener (optional)
  • Sterilized jam jars and lids


  • If you're using gelatin to salvage a batch of jam that failed to set, just soften the correct amount of gelatin powder and stir it in. Don't add any additional sweeteners.
  • Jam set with gelatin shouldn't be processed in a water bath like normal jams, as the process will weaken the gel. Because of this, gelatin-set jams have a short shelf life. Keep them refrigerated and use them within a month.
  • For a fresher taste, reserve a portion of the raspberries and stir them into the hot jam along with the gelatin.


About the Author

Fred Decker is a trained chef and certified food-safety trainer. Decker wrote for the Saint John, New Brunswick Telegraph-Journal, and has been published in Canada's Hospitality and Foodservice magazine. He's held positions selling computers, insurance and mutual funds, and was educated at Memorial University of Newfoundland and the Northern Alberta Institute of Technology.

Photo Credits

  • Pixland/Pixland/Getty Images