How to Make Fruit Jam without Pectin

You can make summer berry jam with just the fruit, lemon juice, and sugar in about 30 minutes at home.

Jam is made with whole or cut fruit, cooked with sugar until it’s thickened and jammy. How gelled, or firm, the jam becomes depends on the fruit’s naturally occurring pectin or on any additional (usually powdered) pectin, which is incorporated during the cooking process. Depending on the fruit and how it was cut, the final product can be completely smooth or chunky with smaller, jammy pieces of fruit throughout. It should always be firm enough to spread and soft enough to spoon. 

The best jams strike a balance among three ingredients: fruit, sugar, and acid. Peak-season fruit is thickened with granulated sugar, which, along with an acid like lemon or lime juice, helps enhance its flavor. Achieving the right proportions can be a delicate dance, but it’s one worth mastering.

THE FRUIT

Your final product will be only as good as the raw fruit you start with, so bear in mind the flavor, texture, sweetness, and acidity of what you choose. Taste it to make sure it’s flavorful and well balanced so your jam will be, too. Nearly any fruit can be used, but the best jam comes from juicy specimens with a balance of sweet and tart flavors and high amounts of naturally occurring pectin, like raspberries, blueberries, plums, and apricots.

Resist the urge to use fruit so ripe it’s collapsing under the weight of its own juices: It might seem like an appealing choice, but it contains less pectin than fruit that’s just about to hit peak ripeness. That’s one reason the beginning of any fruit season is actually the best time for preserving.

Unlike store-bought jam, which almost always has additional pectin, a homemade jam may vary from slightly looser to remarkably firm, but trust that you’re letting each fruit be its truest self, becoming as jammy or spreadable as it wants to be.

For our recipes (found below), we’re using 4 pounds of fruit. If it’s a fruit that needs a pit or core removed, the amounts given in the ingredient list reflect how much fruit you should buy, so that after you pit and core, you should have 4 pounds.

THE SUGAR

Aside from preserving the fruit, the sugar in the jam will also help determine its deliciousness, playing a role in both flavor and texture. Too much, and the jam will be unpalatable, the flavors of the fruit replaced with sickly sweetness. Not enough, and the jam will never achieve the proper texture since fruit does not have enough natural sugar on its own to adequately gel.

THE ACID

Adding acid in the form of fresh lemon or lime juice is important for two reasons: First, it makes for a more well-balanced jam, returning some of the acidity lost with the addition of sugar. Second, pectin needs acid to properly activate, or firm up. The lemon or lime juice is added at the end to preserve its fresh tang and bright citrus flavors. Here, we’re adding about 1 tablespoon of lemon or lime juice per pound of fruit. The exception is our tomato jam, which uses 1 tablespoon of vinegar.

Cooking the Jam

It should go without saying that the most important part of the jam-making process is cooking the fruit (since, well, it’s what makes it jam). This is when water evaporates, not only thickening the mixture but concentrating flavors. Stay alert here: You want that perfect texture — not firm or bouncy, syrupy or pourable.

How To Make Easy Fruit Jam

Makes 2 (8-ounce) jars

Ingredients

5 cups fresh berries (about 1 pound), such as blueberries, blackberries, or strawberries

1/2 cup granulated sugar

2 tablespoons freshly squeezed lemon juice

Pinch salt

Equipment

2 or 3 metal spoons

Knife and cutting board

Measuring cups and spoons

2- to 3-quart heavy-bottomed pot

Potato masher or large fork

Heatproof spatula or wooden spoon

2 clean (8-ounce) jars with lids

Instructions

Prepare the berries. Cut the berries into large chunks, discarding any heavily bruised sections. Place a few clean metal spoons in the freezer.

Combine the fruit and sugar in a medium pot. Place the fruit, sugar, lemon, and salt in a 2- to 3-quart heavy-bottomed pot over medium heat and mash the fruit a little with a potato masher or large fork into a chunky texture.

Cook the fruit and sugar. Bring the mixture up to a boil, stirring frequently. Continue to boil while keeping an eye on it, still stirring frequently, until the fruit is jammy and thick, about 20 minutes.

Begin checking the fruit for doneness. Start checking to see if the jam is set. Remove a spoon from the freezer and dribble several drops of the jam onto the spoon. Wait a few seconds, and then run a finger through the jam. If it leaves a distinct track in the jam, it is done. If it runs back in on itself, keep cooking the jam and test again a few minutes later.

Cool the jam and move it to two jars. Turn off the heat and carefully transfer the jam into 2 clean (8-ounce) glass jars. Cool to room temperature. Seal, label with the fruit and the date and store it in the refrigerator for up to 3 weeks.

Recipe Notes：

Freezing this jam: You can also freeze this jam for up to 3 months. Just be sure to leave 1/2-inch of room at the top of the jar so the jam can expand while freezing.

References:

https://www.thekitchn.com/how-to-make-basic-fruit-jam-cooking-lessons-from-the-kitchn-193560

https://cooking.nytimes.com/guides/45-how-to-make-jam