How to tell when jam is set
Even with a solid recipe, good ingredients and the right equipment, telling when a jam or jelly is set can be tricky. If you don’t cook it long enough you can end up with fruit sauce. If you cook it too long you have a gummy spread on the verge of fruit leather. If you’re using the quick-cook method and commercial pectin, you won’t necessarily need to check for set. Just follow the package directions or a trusted recipe with accurate timing. Long-cook recipes, which use no added pectin, can’t be precisely timed. They’re more art than science and require confirmation from the cook.
Three Classic Ways to Tell When Jam or Jelly is Set
- Thermometer method: The surest way to tell if jam is set is to use a candy thermometer. The jelly stage is 220°F. It’s a nice round number and fairly easy to remember. However, some people find true jelly set a bit firm. If a looser jam is more your style, feel free to pull the preserves off the heat before they reach this stage. It’s safe since it’s well past the boiling point. If you’re new to home preserves and still finding your way, once the jam begins to look set, fill jars at different temperatures and see which texture you like the best.
- Sheeting: The way the jam or jelly drips from a spoon is a useful visual clue. Just stir the jam, lift the spoon so it’s on its side with the bowl facing you and watch. Runny jam will fall from the spoon in individual drops. When it’s set, the drops will slide together and fall from the spoon in a unified “sheet.”
- Chilled Plate: When you begin to cook the preserves just place a few small saucers into the freeze to chill. When you think the jam is set, put a heaping teaspoon of jam onto one of the cold saucers. Wait a couple of seconds for the jam to cool, then push it with your finger. If it wrinkles, it’s done. If your finger just slides through the jam, it needs more cooking. Continue testing on chilled saucers until the jam wrinkles.
Clues your jam needs more cooking
If a watched pot never boils, then a tested jam never sets. If you’re impatient like me, you want to start testing the second the jam hits the boil. Don’t. It’ll just drive you crazy. Fortunately, there are ways to tell whether or not it’s reaching the set point. Pay attention to these and your jam just might pass the sheeting or chilled plate test on the first pass.
Keep cooking your jam if:
- You have more jam than the recipe says. Most modern recipes indicate yield and are fairly accurate — give or take a partial jar or two. If you have way too much jam to fill the allotted jars, keep cooking.
- There’s lots of steam while the jam cooks indicates there is a lot of moisture left in the fruit. Wispy threads of steam indicate you’re nearing the set stage.
- The fruit is floating on the surface and there is lots of foam. Jam changes consistency. As it reaches the set stage, the fruit will sink, there will be less foam to skim off and the jam develop a varnish-like a glossy shine.
- The jam is bright. As long-cook jams near the set stage, the colour will deepen and become darker.
Do you have any tricks that tell you when the jam or jelly is set? Or do you prefer to use commercial pectin?
Next up: Some recipes. Finally!