Low-Sugar Strawberry Freezer Jam + Tips & Tricks to Setting Jam
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One of the supermarkets in my area had a ridiculously good deal on strawberries. $3.99 per flat! For those who don’t know, a flat is 8 pounds of strawberries! I needed some fruit for a party I was having, but there was plenty to spare, so I decided to make some freezer jam. I searched for a good recipe, & found some I liked, but freaked out about the amount of sugar in almost every recipe I found. I decided to try & make it with less sugar. At first, it was unsuccessful, which I am sure had nothing to do with the sugar & I will tell you why in a minute. Anyway, I ended up with jam that separated as soon as I poured it into my jars: fruit on top & liquid on bottom & I knew it wasn’t going to set. So I added more Pectin & re-heated my mixture & it worked great.
Sugar draws liquid from fruits, which is also known as maceration. When my jam was still runny after my first attempt, the fact that I used less sugar had nothing to do with it. After all, I had used less sugar, so hypothetically, there wouldn’t have been as much liquid drawn from the fruit, right? Maybe or maybe not, but none of that mattered anyway because the sugar is not going to make a jam more thick or less thin; it’s not a thickening agent. The Pectin is the key thickener in jams.
Fruits naturally have Pectin, but the riper the fruit, the less Pectin the fruit naturally has, & strawberries are already lower on the Pectin spectrum. Heat makes Pectin form into a gel. So when I added more Pectin & re-heated my mixture, the heat helped the Pectin gel up & it worked beautifully. I am pretty confident in saying, if you have runny jam, extra Pectin (start with 1 Tbsp more) AND Heat will fix your problem. Here is some Pectin, fruit, & jam science facts for you: “When dissolved and let cool, Pectin forms invisible strands that hold liquid in. Acid (such as lemon juice) helps draw even more Pectin out of fruit when it is heated. Water is attracted to sugar. Adding sugar causes some water to be drawn to the sugar molecules, leaving the Pectin molecules free to more easily get at and bind with each other, setting the preserve.”
So now that you know why you might be having problems with strawberry jam setting, you can go ahead & try this recipe! I hope it brings you success!
Low-Sugar Strawberry Freezer Jam
- 3 1/3 cups crushed strawberries (2lbs strawberries)
- 2 Tbsp lemon juice
- 6 Tbsp Ball Classic Pectin OR 3 Tbsp Low or No Sugar Needed Pectin (equivalent to about 1 box of other brand pectin)
- 1 1/2 cups sugar
- Wash, hull & crush strawberries in a LARGE (10 to 14-cup) microwaveable bowl to equal 3⅓ cups. You may use a potato masher, food chopper, or food processor to crush the strawberries; do not puree--leave slightly chunky. Add lemon juice & Pectin. Mix well. Let it sit at room temperature for 20 minutes.
- Add sugar; stir until mostly dissolved. Heat in the microwave on high for 10 minutes until boiling & foamy. (Keep an eye on it so it doesn't boil over.) Remove & stir one last time. Mixture will still be thin.
- Skim the foam off the top, then pour jam into clean freezer containers leaving ½" head space for expansion. Your jam should look consistently chunky throughout the jar after it is poured into the jars. If the fruit has risen to the top & the liquid remains at the bottom, pour the fruit back into the bowl, add one tablespoon more Pectin & heat again until boiling & foamy.
- Immediately top with lids & let stand at room temperature for 1 to 2 hours to cool down before placing in the freezer. Refrigerate up to 3 weeks or freeze up to 1 year.
- *To use freezer jam: Pull from the freezer, allow to thaw in the fridge, & use like store-bought jam. (The freezer is for storing purposes, since jam was not canned in a hot water bath.)
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Recipe altered from Six Sisters’ Stuff