Capture the fleeting tart cherry season with a batch of whole fruit, sweet and tangy low sugar sour cherry jam.
Last week, I made a small batch of low sugar sour cherry jam live on Facebook, using Pomona’s pectin for set. When people asked me about the recipe, I told them it was already up on the blog from last summer. Because I was absolutely convinced that this was a recipe I’d already published.
However, I started to hear from people that they couldn’t find it. Was I sure that it was on the blog?
Turns out, I never wrote a low sugar sour cherry jam recipe. It must have been a dream. I’ve made this style of preserve a bunch of times over the years and really thought I’d shared it. Oops!
So, let’s dig in. Like so much of my jam making, the recipe you’ll find at the bottom of the post is built on a ratio. For these batches of low sugar jam, I use four parts fruit to one part sugar. You could always drop the sugar level a bit lower, but I find that this ratio leaves me with a jam that is nicely balanced between sweet and tart, and holds its color beautifully.
Two questions come up when I talk about making jam by ratio. The first is, are we talking about calculating by weight or by volume? Because I love my kitchen scale, I typically use weight to work out the proportions. But you can also use volume. The trick is to be consistent. If you start with weight for your produce, you use weight for your sweetener. Same goes for volume. Stick with what you start with.
Second question is about measuring before or after you prep your fruit. Here’s the honest truth. As long as you aren’t doing a massive amount of culling, your batch size is pretty generous, and you’re measuring by weight, it doesn’t matter too much. I weighed this batch of fruit before I started pitting and I had 5 pounds, two ounces. After pitting, I had 4 pounds, 15 ounces. In this large-ish batch, those three ounces won’t impact the finished outcome much.
Now, if you’re measuring by volume, prepping the fruit first is the best course of action, because it’s going to fill the measuring cup best. Additionally, if you’re using seconds and so need to do a lot of culling, doing all your necessary peeling, pitting, hulling, trimming, and chopping before you start measuring and calculating.
Now, for the pectin. I like to use less pectin that the Pomona’s packet instructions call for. Typically, I use between 1/2 and 3/4 teaspoon calcium water and pectin for every pound of fruit. Use less for a soft set and a bit more for a firmer set.
Once all the pitting, prepping, and calculating is done, I combine the fruit with the bulk of the sugar the jam will use. I save out about half a cup to use as the medium with which to integrate the pectin. Then it’s time to cook!
- 5 pounds sour cherries, pitted
- 1 pound, 3 ounces granulated sugar
- 1 tablespoon + 1 teaspoon calcium water
- 1 tablespoon + 1 teaspoon Pomona's Pectin
- Prepare a boiling water bath canner and enough jars to hold 4 pints.
- In a low, wide, non-reactive pot, combine the pitted cherries, 1 pound of sugar, and all the calcium water.
- Set pot over high heat and bring to a rolling boil. Reduce heat to medium-high and cook at a vigorous boil for 20 to 25 minutes, until the volume has reduced by at least one-third.
- Stir pectin into the remaining sugar and stream it into the cooking jam, using a whisk to stir to help prevent clumps.
- Return the contents of the pot to an active boil and cook for an additional 2 minutes and then start looking for signs of thickening (it should be pretty clear as Pomona's pectin sets quickly). Once you see some thickening, remove the pot from the heat.
- Funnel the jam into the prepared jars, leaving 1/2 inch headspace. Wipe the rims, apply lids and rings, and process in a boiling water bath canner for 10 minutes.
- When the time is up, remove the jars and set them on a folded kitchen towel to cool. When the jars have cooled enough that you can comfortably handle them, check the seals. Sealed jars can be stored at room temperature for up to a year. Any unsealed jars should be refrigerated and used promptly.