How To Make Freezer Jam

Summer offers fresh fruits at their best. Let’s preserve some for later!

Strawberry Freezer Jam

Photo by Tricia Winterle Jaeger

Freezer jam is easy to make. And because freezer jam isn’t cooked, it tastes remarkably like fresh fruit.

The Ingredients

There are just a few ingredients:

Fruit Use perfectly ripe fruit. Since you won’t be cooking it, the flavor of the jam is going to be much like the flavor of the fruit. If it’s over- or underripe, you’ll be able to taste it. Jam made with underripe fruit, besides being sour, might jell too much, while jam made with overripe fruit–besides having an off-flavor–might not jell enough.

Pectin Most recipes call for additional pectin to thicken the jam, giving it that familiar jammy consistency. Commercially produced pectin is derived from fruit–usually apples or citrus. Store-bought pectin comes in two forms: powder and liquid. Most recipes call for powdered pectin, but these are not interchangeable–use whichever form your recipe calls for.

The basic ratios for each packet of powdered pectin are:

  • 3 cups mashed fruit
  • 5 cups sugar, and
  • 1 cup water in which to dissolve and boil the pectin.

This formula can vary a little depending on the brand of pectin, so follow the instructions on the package.

Sugar Sugar inhibits the growth of bacteria, keeping your jam fresh, fruity, and safe to eat. Jam recipes are formulated to call for a certain ratio of pectin to sugar, and they will not jell properly if you don’t use the correct amount of sugar. If you’d like to make less-sweet jam, you’ll need to buy a special kind of pectin that’s formulated to work with less sugar.

Containers

Before you begin making the jam, have all your jam jars ready and waiting. Use either sturdy plastic containers with tight-fitting lids, or short, wide-mouthed glass jars made especially for the freezer.

It’s best to choose containers that are no bigger than pint-size; the jam will not set up as well in larger containers. Wash them as you would any other dishes; there’s no need to boil them like with traditional jam-making.

Rose Hip Freezer Jam

Photo by Cazuela

Making Jam

The process itself is simple:

  • Wash and stem the fruit (and peel it, if applicable).
  • Place it in a wide-bottomed pan and crush with a potato masher to a smooth consistency, leaving some chunks of fruit if you like.
  • Stir in the sugar and let the mixture sit for 20 minutes, stirring occasionally.
  • In the meantime, mix together the pectin and water in a small saucepan until the powder is dissolved; bring it to a boil over high heat, and let it boil for a full minute.
  • Pour it into the fruit and stir for a couple of minutes.
  • Pour the jam into your containers, leaving a half-inch of “headspace” at the top.
  • Cover the containers and let them sit at room temperature for 24 hours.
  • The jam should thicken significantly overnight, but the jelling process can take up to two weeks to complete. If it’s too thick, stirring it will soften it up. If it’s still too runny after two weeks, pour it into a saucepan and bring it to a boil. It will get thicker as it cools, and you can re-bottle as before.
Jalapeno Strawberry Jam

Photo by jpepp

Storing Your Jam

As the name implies, freezer jam is meant to be stored in the freezer. In fact, it will keep beautifully in the freezer for up to a year. You can also keep freezer jam in the refrigerator for up to three weeks. Once you open a container of jam, you should use it within three weeks as well. Just remember never to keep freezer jam at room temperature, or it will spoil.