Why is my marmalade hard almost like candy once refrigerated?

I've been trying to make this kumquat marmalade in the microwave from a recipe that I found online. It's super easy and I just heat the marmalade mixture until the mixture hits 220 and passes the gel test on a cold plate. But twice now, the marmalade is like super thick candy once refrigerated. It's delicious if you can dig it out, but totally not spreadable at all. What am I doing wrong?

  • Posted by: Tashie
  • April 10, 2011


Tashie April 12, 2011
thank you so much! yes, the recipe clearly was way easy and didn't delve into this jellying stuff. my kumquat candy is delicious though :)
betteirene April 11, 2011
Everything sfmiller wrote is true, but wait. . .there's more.

To get around an inaccurate thermometer: Boil a quart of water with your thermometer attached to the pot. When it comes to a full boil, note the temperature reading. For jam, jelly, marmalade and preserves, add 8 degrees to that temperature. If your jelly gets hotter than that, you are on your way to making caramel or lollipops.

Besides overcooking, caramelized jelly can be caused by too much pectin (the kumquats weren't ripe enough or the recipe's fruit-to-pectin ration is off). It coiuld also be that the mixture was cooked too long before it reached the jellying point, which happens when too little sugar is called for.

A good jelly depends on so many complex factors that it's not always possible to give just one answer to a question about problems. Using a recipe with accurate directions from a reliable source is one way to ensure success but does not guarantee it because fruit varies widely in jellying quality. Plus, even if you followed the recipe's directions to the letter, your microwave might be more (or less) powerful the the recipe writer's, which would also affect the outcome.

Making jelly is science. It should not be super easy, it should not be made in the microwave and it should not be made from just any old recipe found online, not even your grandmother's blog, unless it is from the USDA, a university extension service or another trusted source that tests recipes before publishing them, like Better Homes and Gardens or Martha Stewart.

The fact that you've made the recipe twice with the same results both times makes me want to blame the recipe, not you.
sfmiller April 10, 2011
You're cooking it past the jelling point. A few possibilities:

1. Your thermometer could be inaccurate. Test it in rapidly boiling water.
2. Microwaves heat unevenly, so when part of the liquid registers 220, another part of it is hotter.
3. If you're at high altitude, the jelling point is reached at lower temperatures, so you'll need to take the liquid off heat sooner.than 220.
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