Is there really such a thing as “sugar-free” jam? With all the sugar in the fruit itself, it’s technically impossible. But you can make jam without refined sugar. All you need is fruit, fruit juice concentrate, and pectin that’s specially made for no- or low-sugar preserves, like Pomona’s. (You can also make jam with honey or a variety of other alternative sweeteners. One good resource to explore is the book 
Last week, a question about the benefits of making no-sugar-added jam arose on the Facebook page for Food in Jars. Someone wisely asked:
Isn’t refined sugar and concentrated fruit juice just about the same calorie-wise and the impact on your metabolism about the same? The sugars in concentrated fruit juice are just as potent as white sugar I would think.
I don’t have a perfect answer:
I’ve been asking myself the same question, even as I experiment with making jams without refined sugar. I see a lot of sources that say fruit juices are okay for diabetic folks as long as they are carefully monitored in an overall tally of carbs. I also know many people who are sugar-free (because they’re diabetic, pre-diabetic, or otherwise) who say they’re okay with moderate amounts of a jam that’s only fruit-juice sweetened, so I’m trying to do this for them. Still, it seems like a lot of it comes down to how much of any type of jam you eat.
If you’re interested — for any reason — in making a jam without refined sugar, I think this is a nice one. The flavor of the fruit is clear and the lemon zest gives it a nice pop. Sometimes boxed pectin does odd things to a jam’s set — making it overly firm or gelatinous — but I didn’t find that to be true here. (Blueberries seem to be very versatile and forgiving in a sugar-free setting.) True, it’s not the luscious, glossy texture you’ll get from a fully sugared preserve, but sugar-free jams shouldn’t be compared with their high-society cousins. This down-to-earth little jam knows its place and feels just fine about it.
Sugar-Free Cherry Blueberry Jam
2 cups sweet cherries, pitted and mashed (about 1 1/2 pounds)
1 cup blueberries, mashed (about 12 ounces)
1 tablespoon lemon zest
1/4 cup lemon juice
1 scant teaspoon Splenda (optional)
1 cup apple juice concentrate
4 teaspoons Pomona’s calcium water*
3 teaspoons Pomona’s pectin powder
* The calcium is in the Pomona’s box with the pectin powder, along with instructions about how to prepare the calcium water; it’s easy. I mix mine in advance and store it in the fridge for a few months.
1. Sterilize your jars.
2. Mash the cherries and blueberries and put them in a 6- or 8-quart nonreactive, heavy-bottomed pot. Stir in the lemon zest, lemon juice, Splenda (if desired), and calcium water. (Don’t add the apple juice concentrate yet!)
3. Put the concentrated apple juice in a little saucepan and bring it to a boil. Transfer the boiling juice to a blender or VitaMix and add the pectin powder. Vent the lid and blend the pectin mixture for 1-2 minutes to thoroughly dissolve the powder.
4. Bring the fruit mixture to a boil, add the pectin solution, and cook, stirring constantly, for exactly 1 minute. Bring the mixture back to a boil and then remove it from the heat.
5. Allow the jam to cool 5-8 minutes, occasionally giving it a gentle stir. This step is important; it will minimize “fruit float” — that is, the annoying tendency for the fruit solids to separate from the liquid and float to the top of the jar during processing.
6. Pour the jam into sterilized jars, leaving 1/4-inch head space. Wipe the rims clean before adding lids, and process 10 minutes in a boiling water bath.
Makes 4 half-pint jars
