When summer comes around, we try to find ways to make it last forever. So every day this week, we'll bring you a new guide to preserving the season's best herbs, fruits, and vegetables. Today: How to make your own fruit jam.
Why make your own jam? It’s a simple way to use up any bumper crop of fruit. It’s a no-brainer D.I.Y. gift. But we like it most because it lets us control the level of sweetness in the final product. (Raspberry jam should taste like raspberries, not raspberry sugar.) For peak jamminess, choose fruit that’s at its height but not overly ripe; older fruit has lower acid and less pectin, which yields a runny, one-note jam that will bum out any piece of toast. Choose from our Raspberry-Rose Jam or Apricot-Riesling Jam, and get cooking. Here's what you need to know:
Jam: Chopped fruit is cooked with sugar to get a chunky, relatively thick result. (To make jelly, the cooked mixture is passed through a jelly bag.)
Pectin: It’s what causes jam and jelly to gel. Naturally occurring in lots of fruit, especially grapes, apples, cherries, and citrus; you can also buy it in powdered form.
Set: This refers to how hard or soft the preserve is. A “hard set” means a stiff jam, while a “soft set” means it will be spreadable.
Spoon a bit of jam onto a chilled saucer, refrigerate it for two minutes, then drag your finger through it. The mixture should be homogenous, with no liquid seeping out. Still runny? Simmer a few minutes longer and try again. Just be careful: It is possible to overcook jam. If subjected to too much heat, pectin loses its setting power.
Some fruit has a higher sugar content, depending on ripeness and variety. If your mixture tastes way too sweet, adjust it with a touch of acid. Give it a spritz of lemon juice or even a splash of fruit vinegar right before you remove it from the heat, and your jam will go from flat to kick-out-the-jams bold.
We get it: Canning may seem intimidating—the equipment! the boiling water!—but the truth is you need little more than a large pot, a dish towel, a jar lifter, and, okay, boiling water to preserve like your great-grandmother did. Just follow our easy step-by-step guide and you’ll still be spreading August’s jam come February.
1. Start with sterilized jars (boil them for 10 minutes). Ladle in hot jam or pickling liquid, or use a wide-mouth funnel, leaving headspace based on recipe. Clean the rim with a damp paper towel.
2. Place the lid on the jar and screw the band on just enough to hold it in place (but not super tight—the contents can expand, and if there’s no room to move, crack goes the jar).
3. Line the bottom of a large pot with a kitchen towel (to protect the jars), and fill it with about 4" of water. Bring to a simmer, then carefully lower jars into the pot, spacing about 1" apart.
4. If water does not cover jars by 1–2" after adding them to the pot, have a kettle going and add more boiling water to submerge them. Remember, you want to sterilize the entire jar, including the lid.
5. Simmer jars for 10–20 minutes, depending on the recipe (for fruit jams, 10 minutes will do). Remove with a jar lifter that has a rubber grip and place about 1" apart on a towel-lined surface. Let cool.
6. Once completely cool, test the seal by pressing on the lid: It shouldn’t flex up and down, therefore no air can get in (the crux of canning).
7. Tighten the band on the jar, label, and store in a cool, dark place for up to a year.
Raspberry-Rose Jam
Apricot-Riesling Jam
