How to Make Sugar-Free Jam or Preserves

Grab a Flat of Berries, Try Both Methods and See Which You Like Best

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There is nothing quite like homemade jam. It seems to taste so much more like the fruit it came from than jams you buy at the store. If making your own jam or preserves is what you have always wanted to attempt, but were daunted by the process, there are two approaches you should give a try—boiling and adding gelatin. 

Jams do not have to break the carb or sugar bank either, you can make it sugar-free, too.

Store-bought jam is mostly sugar, and in fact, jam is one of those things that is tricky to make sugar-free. Sugar gives jam its characteristic mouthfeel, and it acts as a preservative. However,  you can successfully make a sugar-free jam or preserve, it takes patience and a little experimentation.

Berries on a Low-Carb Diet

Of all the fruits, berries, like strawberries and blackberries, are among the lowest in carbohydrates and sugar. The great news is they taste sweet, and can still be enjoyed on a low-carb diet.

At the height of berry season, grab a flat of your favorite berries. Eat some and get ready to preserve the rest.

Some Considerations Before You Begin

Since sugar is usually what preserves jam, and you are going for a sugar-free version, you will want to make “freezer jam” in order to keep it longer than a couple of weeks. Generally, it will keep in the fridge for two weeks, but any jam you want to keep longer than that should be stored in the freezer.

Sugar-free jam in stores can stay on the shelf because of the added preservatives. 

Another ingredient in most jams is commercial pectin, which has sugar in it. Some fruits, such as plums, have enough natural-occurring pectin, it is a natural thickener, that you do not need to add any, but berries generally need to have pectin added.

Blackberries have some of their own pectins but strawberries have essentially none. Sugar-free commercial pectin does exist, but it can sometimes be hard to find.

There are a few methods for making jams and preserves. Let's take a look at the boiling method and using gelatin. You can try both and do side-by-side comparisons.

Boil it Down (Use Blackberries)

Try the simplest method first, boiling. Get two cups of berries, add some water and artificial sweetener, like the liquid form of Splenda which does not have the off-flavor and extra carbs of the powder form, and boil the berries until they reduce. The natural pectin in blackberries helps produce a concentrated, spreadable puree. Two cups of berries yield 1/2 cup of jam.

By using the boiling method, the result is not as "jammy" as the other methods, it is more like a spread. But, it is the easiest method. Perhaps because of the lack of pectin, strawberries are not good to use with this technique. If you want to try using strawberries instead of blackberries, it might be best to add a commercial, sugar-free pectin to the recipe.

Use Gelatin

You can make a sugar-free strawberry jam using strawberry Jell-O, but if you want the fresh fruit flavor to be the star, use unflavored gelatin.

For blackberries, you need a bit less than a packet, like a little less than 2 teaspoons, which works well for two cups of blackberries mixed with 2/3 cup of water and sweetener to taste. Boil it down, add gelatin. This mixture produced a little less than a cup and a half of jam. The consistency is good, it is a little “bouncy," and needs to be stirred. It produces a credible and spreadable jam.

Again, strawberries do not fare as well, perhaps because of the lack of natural pectin, but the strawberries still work. Use a full packet of gelatin, a little more than 2 teaspoons, for 1 cup of puree produced by blending 2 cups of chopped strawberries with half a cup of water.

It tastes good, it is spreadable, but the consistency is somewhat lacking. Experimentation is key, you can try varying cooking times to see if you can get the right consistency.