What To Do When Your Jam Doesn't Jiggle

August 11, 2017

My grandma makes the best raspberry jam. I’m not biased. It’s an objective fact. Every September, she bustles about her kitchen filling mason jars with ruby red deliciousness, which she then ships across the country to her beloved grandchildren. But even with years of practice, Grandma has off days, when her jam doesn’t set.

Turns out there are quite a few possibilities why Grandma’s jams don’t jiggle, as explained in Sarah Owens’ Toast and Jam. While the self-taught baker wowed the culinary world with her James Beard Award–winning Sourdough in 2016, her latest book features both rustic baked breads and their toppings, sweet and savory.

"I prefer a softer, almost silky set and often leave the the pectin out altogether to make a syrup,” she writes. But if you want your jams, jellies, and preserves to gel, consider these four culprits before repurposing:

Not enough pectin

Pectin is a water-soluble fiber concentrated in the skins and cores of fruit that gives jams their gel. While all fruits make equally delicious jams, they don’t all have equal amounts of naturally-occurring pectin. Some, like blueberries, peaches, or strawberries, naturally contain less pectin, while others, like apples and citrus fruits, are naturally pectin-rich. But as fruit ripens, enzymes begin to break pectin down, making fruit softer and more difficult to gel. If preserving low-pectin or very ripe fruit, try adding an additional teaspoon or tablespoon of pectin, available at most grocery stores in the baking aisle.

Not enough sugar

You may hesitate to add sugar to already sweet fruit, but pectin needs the sweet stuff to set properly. If you use a no or low-sugar pectin and your jam is still liquidy, add 1/4 to 1/2 cup more sugar.

Not enough acid

In order for pectin to bond with sugar and fiber at 220° F, pectin also needs acid. For a firmer consistency, try adding 1 to 2 more tablespoons of white vinegar or lemon juice.


Too much heat will start to break down pectin’s structure (and keep your jam from setting), while not enough heat won't let the water evaporate (and keep your jam from setting). After stirring pectin into the hot mixture, you should cook it for only 1 to 3 minutes before reaching a setting point at 220°F.

Don’t want to buy pectin? Make your own!

When making jams with high sugar content, you can use homemade pectin. To make your own pectin stock, quarter under-ripe green or crab apples. Place into a stock pot filled with water, then bring to a gentle boil over medium-high heat, cover, and cook for 30 minutes. Once the apples are soft, strain the mixture through a mesh sieve into a large bowl. You can use the "pectinified" liquid to replace water in high-sugar jam recipes.

Now it's your time to jam!

Do you have any tips or tricks to ensure your preserves set? Any favorite no-fail recipes? Let us know in the comments!

See what other Food52 readers are saying.

  • Greenstuff
  • AntoniaJames
  • Stephanie G
    Stephanie G
  • Mrs Beryl Patmore
    Mrs Beryl Patmore
Katie is a food writer and editor who loves cheesy puns and cheesy cheese.


Greenstuff August 11, 2017
The most important thing anyone can do is to make jams often enough to get a feel for them. Or to be totally accepting of divergent results. I come from a family of jam makers, and it's amazing to see our range of techniques. Pectin vs. natural. Thermometer vs. dripping from a spoon. They can all work, and equally, they can fail. I learned that a couple of years ago, when I decided that after many years, I should rely on my pricy instant-read thermometer instead of my eyes. Major fail! But we ate it up, so it's good to remember that even failures can be successes if they taste good.
AntoniaJames August 11, 2017
Well put, Greenstuff. I've had my fair share of super-runny jams -- which work nicely to flavor yogurts or to drizzle on pancakes and waffles -- and have made some super-stiff ones too, which I've been known to mix with thinner jams involving different fruit and then re-can, with great results! ;o)
Stephanie G. August 11, 2017
Well said, Greenstuff!
Greenstuff August 12, 2017
Thanks, Katie! We make whatever is in our gardens or we can legally glean, and since we've all lived in different places, it's made for a pretty wide range of the usual, like blackberries and strawberries, to the more exotic, like mountain ash and rose hips. No specific recipes--one of my brothers swears by commercial pectin, while I'll go to any length to avoid it.
AntoniaJames August 11, 2017
For several decades, I used Pomona pectin regularly. I never use commercial pectin anymore, and have had inconsistent results with pectin made from apples. Influenced largely by several recipes of Mme Ferber and Paul Virant (The Preservation Kitchen), I always (always!) macerate the fruit overnight, and then in the morning, strain it over a colander, and boil down the syrup until it is thick and the tiny boiling bubbles start to pop quite rapidly. I put a saucer in the freezer at that point. Then I add the fruit back and cook it again, stirring frequently to prevent scorching, until the jam reaches the same bubble popping point. I test the set by dropping a small blob on the cold saucer and put it back in the freezer for about a minute. I run my finger tip through the blob; if the line it makes doesn't fill in right away, the jam is set. This is how people have been making jam without pectin and without thermometers for generations.
My second tip is to help out low pectin fruits with one or both of the following: the pips (seeds) of lemons are full of citrus. I save all the lemon seeds that I'd otherwise throw away during the early weeks of the summer, freezing them until needed. I wrap them in a piece of cheesecloth, pour 1/2 cup of hot water over the bundle and let it sit overnight. In the morning, I squeeze the white gel out of the cheesecloth bag into the water and use that in my jam.
Another natural source of pectin is the skin of plums, which also happen to work brilliantly to improve the flavor of any jam. You don't taste plum; you just taste great jam. (Thanks, Rachel Saunders, for this tip.) I often will blitz up a plum or two and scrape the skins, pulp and juice into the liquid from the other fruit that I cook at the outset. NB: the oval Italian plums, I read somewhere, don't have as much pectin.
Hope this helps. ;o)
Mrs B. August 12, 2017
Oops. I meant to say the pips are full of pectin. The actual gel that they create just from soaking is quite amazing. ;o)