Jelly, Jam, and Preserves

The consensus is that an unopened jar of jelly, jam, or preserves has a shelf life of at least a year if kept in a cool,  dry place.  How long will it remain safe and appealing once it’s opened?  Answers vary from  1 to 12 months.  Why so much variation?  The  shelf life of the product is affected by many factors including these: the type of fruit, the amount of sugar and preservatives, whether it is a homemade or a commercial product, and how the product is handled by the consumer. 

The Smuckers Consumers Relations phone message gives the following statistics: For unopened jars, consult the “best if used by” date.  For opened jars: traditional and low sugar: 12 months; Simply Fruit and Sugar-free: 9 months; apple butter: 15 months.  Note that these figures are a bit more generous than those in our chart below, Virginia State University (Virginia Tech). However, the message is that store-bought jelly, jams, and preserves will last several months if properly handled in the home.

Here’s a summary of suggestions and explanations about open jars of jelly and similar fruit products from our site’s consultant, food scientist Susan Brewer:

Commercially prepared jellies (and jams) have a controlled acidity and often preservatives in addition to a standard amount of sugar/fruit/liquid.  All of these contribute to their stability.  The proportions are designed to prevent syneresis (weeping), so they maintain their quality longer.   Commercial jellies, like home-canned jellies, should be refrigerated once opened.  Since home canned products aren't nearly as standardized and don't contain mold-inhibitors, you can't expect them to last nearly as long as the commercial products.  

Keeping the container out at room temperature often or for long periods of time will reduce the expected shelf life. When jam or jelly is to be used, spoon out the quantity that you estimate that you will want into a bowl, and then return the jar to the refrigerator. This minimizes exposure of the whole container to microbial contamination.

Examine the container regularly during storage for signs of spoilage like molds, yeasts, off odors (including a fermented, “yeasty,” or “alcohol” odor) or off-colors once the jar is opened. Discard the entire contents of the container if any of these are detected. Some molds produce dangerous toxins that penetrate down into the food. The most common microorganism that will spoil jelly is mold because it can grow at low water activity (low free water content), low temperatures and over a range of  acidity levels. Whether or not mold will grow depends on whether mold spores get into the product, how long it is left out (at room temperature) and how much contact it has with various implements (knives, spoons).

Sugar is a primary preservative in jams and jellies because it ties up the water, so bacteria can’t use it. Lower-sugar or no-sugar-added spreads made with “lite” pectin have more “available” water and  a shorter refrigerator shelf life than those made with the traditional amounts of sugar. Also, deterioration of flavor and color generally occurs more rapidly in “lite” jams and jellies because they contain less sugar than the traditional products.