How Long Does Homemade Jam Last?

New to jam? Start with how to make jam, step by step.

Homemade jam keeps well, which is the whole point of making it. Here is what to expect, and how to know when a jar is past its best.

Sealed and stored in the pantry

A properly filled and sealed jar of high-acid jam keeps its quality for about one year in a cool, dark cupboard. It does not become dangerous the day after; the flavor and color simply start to fade over time, so a year is a good rule for eating it at its best. Always label each jar with the fruit and the month you made it. See how to store your preserves for the details.

Once you open a jar

After opening, keep the jar in the refrigerator and use it within about three to four weeks. Always spoon jam out with a clean utensil. A knife that has touched toast or butter introduces crumbs and moisture, which is the fastest way to shorten a jar's life.

How to tell a jar has turned

• The lid has lost its seal, or has bulged or lifted.
• Any mold on the surface, or a fizzy, fermented or off smell.
• An unusual color change or a slippery, cloudy look to the fruit.

When in doubt, throw it out. A jar of jam is not worth second-guessing. This is why a clean fill and a good seal at the start matter so much; our twist-lid Jam Jars are built to seal reliably and to be opened and resealed through the weeks you are working through a jar.