To gel properly, sweet spreads must contain the right combination of fruit, pectin, acid and sugar. The fruit gives each spread its unique flavor and color. Fruit also supplies the water needed to dissolve the other ingredients and some or all of the pectin and acid. Good quality, flavorful fruits make the best sweet spreads. If combined with the right amount of acid and sugar, pectins cause a gel to form.
All fruits contain some pectin.
Apples, crabapples, gooseberries and some plums and grapes contain enough natural pectin to form a gel. Other fruits, like strawberries, cherries and blueberries, contain little natural pectin. They must be mixed with other fruits high in pectin or with commercial pectin products for a gel to form. Fully ripened fruit contains less pectin, so combine it with one-fourth underripe fruit when making sweet spreads without added pectin. Use only in recipes calling for added pectin.