Low-Sugar Raspberry Freezer Jam

Yes it is possible to make low-sugar raspberry freezer jam! I use a modest amount of honey to lightly sweeten the raspberries and the result is a slightly tart, slightly sweet, flavorful jam. If you don’t eat honey – agave or crystalized sugar can also be used. Most jam recipes require an insane amount of sugar in order to get it to set up. This recipe sets up just fine with a fraction of the sweetener. Even still, low-sugar jam is best used sparingly as a condiment – as opposed to eating spoonfuls right out of the jar 😉

Raspberry Jam in jar with fresh raspberries strewn about

We’ve been growing a huge garden of an “ever bearing” variety of raspberries for the past 20 years; the name of the variety is called Caroline. They produce heavily for 6 to 8 weeks each summer, and then less heavily until frost. That’s a lot of berries! We enjoy them fresh by the handfuls – and also add them to our morning oatmeal, cereal, non-dairy yogurt, fruit salads, and the like. I use them to make Fresh Raspberry Tart –  and we also freeze dozens of 1-quart packages each summer to be enjoyed off season.

In addition, I’ve made countless jars of raspberry jam over the years using various methods and recipes. After years of experimenting, this low-sugar raspberry freezer jam is by far my favorite. I altered Pomona’s Universal Pectin recipe slightly. The main difference is I remove half of the raspberry seeds, so the resulting jam isn’t so seed heavy. Until I started doing this, I always felt that the jam was just too gritty. Removing half of the seeds creates the perfect texture.

My Low-Sugar Raspberry Freezer Jam Recipe

Box of Pomona Pectin
  • A modest amount of honey (or agave or crystalized sugar) is used as the sweetener.
  • Seeds are removed from half of the berries to create a better texture.
  • It is made with Pomona Pectin which I feel is a cleaner product compared to other commercial pectins. Most pectins require you add a high ratio of crystalized sugar to raspberries. This pectin allows you to add much less sweetener.

Pomona’s Universal Pectin contains only 100% pure citrus pectin, which is vegan, gluten free, and GMO free. There are no additives, preservatives, sugar, or dextrose. There are no corn or apple by-products.

The monocalcium phosphate powder that comes in its own packet when you purchase Pomona’s is a food-grade rock mineral source of calcium made up of two minerals, calcium and phosphorous.

Pomona’s Universal Pectin

6 half-pints of fresh raspberries
Half-pint containers of raspberries

Method Overview

  • Mix calcium powder with water (unless you already have some made up)
  • Stir pectin into sweetener
  • Mash half of raspberries; remove seeds from other half of raspberries
  • Combine ingredients and briefly boil

How to remove raspberry seeds

If you use a food mill to remove the raspberry seeds, place it over a bowl to catch the juice. Keep turning the crank (forwards and backwards) until no more juice is released from the berries.

No food mill? No worries. You can also remove the seeds by smashing the berries against a fine mesh strainer. Smash the raspberries against the strainer using the back of a spoon; catch the juice in a bowl. This method is harder than using a food mill, but it works in a pinch.

Raspberries processed using food mill
Using an Oxo food mill to remove seeds from berries and catching the juice in a bowl
Raspberry Jam in jar with fresh raspberries strewn about
Print Recipe
5 from 12 votes

Low-Sugar Raspberry Freezer Jam

Servings: 4 half-pints


  • 1/2 teaspoon Pomona calcium
  • 1/2 cup honey or agave (if you prefer crystalized sugar see note below)
  • 2 teaspoons Pomona pectin
  • 8 half-pints fresh raspberries


To Prepare the Calcium Water

  • Put the 1/2 teaspoon of Pomona calcium powder and 1/2 cup of water into a jar with a tight fitting lid. Shake well and set aside.

To Prepare the Sweetener

  • Measure the sweetener and mix well with the 2 teaspoons of Pomona pectin. Set aside.

To Make the Jam

  • Put 4 half-pints of fresh raspberries into a large heavy bottomed pot. Mash using a potato masher. Cover and set aside.
  • Remove the seeds from the remaining 4 half-pints, reserving the juice. The easiest way to do this is to use a food mill such as the OXO brand. If you don't have a food mill, you can use a fine mesh strainer for this step.
    Pour the reserved raspberry juice into the pot with the mashed raspberries.
  • Add 2 teaspoons of the calcium water to the pot (put the rest of the calcium water into the refrigerator for future use).
  • Cook over medium-high heat, stirring often, until the raspberry mixture begins to boil.
  • Add the sweetener/pectin to the pot. Stir well so the sweetener mixes into the raspberries.
  • Return to a boil. Continue to boil while stirring for another minute, then remove from the heat.
  • Skim any foam that has formed from the surface of the raspberry mixture.
  • Taste the jam at this point to be sure it is sweet enough for your liking. If you want a sweeter jam, add another 1/4 cup of honey (or agave). Stir well until well mixed.

To Freeze the Jam

  • Pour the hot jam into half-pint or 1-pint jars leaving 1/2" of headspace to allow for expansion; cap the jars.
  • Let the jars cool down to room temperature before putting them into the freezer (or refrigerator). Please note that the jam won't gel up until it has cooled.


You can substitute the honey with crystalized sugar. Sugar isn’t as sweet as honey so you’ll need to adjust the amount. Start with 3/4 cup and taste; if necessary add another 1/4 cup.
How many cups are in a pint of raspberries?

A half-pint of raspberries equals approximately 1 cup.

What’s the difference between jam and jelly?

Jelly is made from just the juice which results in a it is a clearer product – and it is a firmly gelled consistency. Jam contains the seeds and pulp, and is of a looser consistency.

How long will the jam last once it is thawed?

It will last about three weeks if kept refrigerated. Use a clean spoon or knife when scooping it from the jar so crumbs, butter, etc. don’t contaminate the jam.

No Comments

    Leave a Reply

    Recipe Rating