Jam and Jelly Basics

• Fruit jams contain whole and mashed fruits, while jellies are soft spreads made from fruit juice. Created by mixing sugar or other sweeteners and sometimes pectin to create a gelled, spreadable product, jams and jellies can be quite diverse. Both are highly acidic products and can safely be processed using a boiling water bath. Follow specific recipe instructions regarding jar size, as not all products are safe for processing in different sized jars. While using smaller jars is acceptable, using larger jars than called for can lead to problems.

Keeping It Safe

• When canning, you should always use tested and approved canning recipes to keep your jam and jelly safe. Quart jars are not recommended in jam and jelly recipes and should be avoided. While the toxic Clostridium botulinum bacteria is not an issue because jams and jellies have a pH lower than 4.6 that inhibits its growth, mold spoilage can be an issue. Because there are no standard processing times developed for jam and jelly in quart jars, don't can in them.

Getting the Right Set

• Another compelling reason to use the most commonly called for 1/4 pint, 1/2 pint and 1 pint jars for jelly and jam making is that they help the jam or jelly set correctly. To achieve a good set with both commercial pectin and homemade pectin, making jam in a small batch and canning it in small jars helps it achieve its thickened, gelled texture that makes it jam or jelly. Without this, it takes longer for the jam or jelly to cool after processing, which in turn can cause it not to set, leaving you with a watery mess.

Staving Off Spoilage

• Unless you use a lot of jam or jelly, a quart jar would not be appropriate as it is likely the product would spoil before you use it all. While most jams and jellies are good for one year when stored in a cool, dark location, opened jam or jelly should be used within a month for the best quality. Low-sugar jams and jellies are prone to faster spoilage and should be used before this time. Always use clean utensils when serving jelly or jam to prevent cross contamination and spoilage in opened jars.