Michigan State University Extension
Preserving Food Safely - 01600959
10/13/97
For proper texture, jellied fruit products require the
correct combination of fruit, pectin, acid and sugar. The
fruit gives each spread its unique flavor and color. It
also supplies the water to dissolve the rest of the
necessary ingredients and furnishes some or all of the
pectin and acid. Good-quality, flavorful fruits make the
best jellied products.
Pectins are substances in fruits that form a gel if
they are in the right combination with acid and sugar. All
fruits contain some pectin. Apples, crab apples,
gooseberries and some plums and grapes usually contain
enough natural pectin to form a gel. Other fruits, such as
strawberries, cherries and blueberries, contain little
pectin and must be combined with other fruits high in pectin
or with commercial pectin products to obtain gels. Because
fully ripened fruit has less pectin, one-fourth of the fruit
used in making jellies without added pectin should be
underripe.
The proper level of acidity is critical to gel
formation. If there is too little acid, the gel will never
set; if there is too much acid, the gel will lose liquid
(weep). For fruits low in acid, add lemon juice or other
acid ingredients as directed. Commercial pectin products
contain acids which help to ensure gelling.
Sugar serves as a preserving agent, contributes flavor
and aids in gelling. Cane and beet sugar are the usual
sources of sugar for jelly or jam. Corn syrup and honey may
be used to replace part of the sugar in recipes, but too
much will mask the fruit flavor and alter the gel structure.
Use tested recipes for replacing sugar with honey and corn
syrup. Do not try to reduce the amount of sugar in
traditional recipes. Too little sugar prevents gelling and
may allow yeasts and molds to grow.