What is freezer jam?

Freezer jam is made with fruit and a type of pectin that can form a gel with much less sugar than the pectin used in regular jelly and jam.   Traditional jams and jellies (except the low calorie kind) are made with a kind of pectin that has to be “dehydrated” by sugar in order for the pectin molecules to bond to each other and gel. (Pectin, a thickener, is available in liquid and powder form.) The ingredients are mixed together (not cooked), poured into jars, and kept frozen until it’s time to consume the product.  The mixture can be put into an ordinary glass canning jar or a freezer container leaving some space for expansion.  (Water expands by ~10% in volume when it freezes.) 

Freezer jam can be allowed to gel either before or after freezing.  It is not shelf stable (except in the freezer)  because it has  much less sugar to preserve it. In addition, it hasn’t been cooked (boiled) like jellies made with traditional pectins.

Source(s):

Susan Brewer, Ph.D.,  University of Illinois, Department of Food Science and Human Nutrition

Link(s):

About.com  “How to Make Freezer Jam”