When Your Jelly Doesn't Set

There are four possible reasons why the jelly is too soft.
  1. Avoid overcooking the fruit to extract the juice, this lowers jelling capacity of pectin.
  2. Incorrect proportions of sugar and juice may cause jelly to be soft. Follow recommended instructions, don’t reduce sugar in recipes using commercial pectin.
  3. Undercooking may cause soft jelly. Cook rapidly to jelling point and time boil accurately when using commercial pectin.
  4. To little acid may cause soft jelly. Avoid using fruit that is overripe. Add lemon juice if needed to increase acid.

Remaking Jelly and Jams

Measure jelly to be recooked. Work with no more than 4 to 6 cups at a time.

To remake with powdered pectin
For each quart of jelly, mix 1/4 cup sugar, 1/2 cup water, 2 tablespoons bottled lemon juice and 4 teaspoons powdered pectin. Bring to a boil while stirring. Add jelly and bring to a rolling boil over high heat, stirring constantly. Boil hard 1/2 minute. Remove from heat, quickly skim off foam and pour into sterilized jars. Leave 1/4-inch headspace. Adjust new lids and process the jars for 5 minutes in a boiling water canner.

To remake with liquid pectin
For each quart of jelly, measure 3/4 cup sugar, 2 tablespoons bottled lemon juice, and 2 tablespoons liquid pectin. Bring jelly only to boil over high heat, while stirring. Remove from heat and quickly add the sugar, lemon juice, and pectin. Bring to full rolling boil, stirring constantly. Boil hard for 1 minute, then remove from heat. Quickly skim off foam and fill sterilized jars. Leave 1/4-inch headspace. Adjust new lids and process the jars.

To remake without added pectin
For each quart of jelly, add 2 tablespoons bottled lemon juice. Heat to boiling and boil for three to four minutes. Use one of the tests described above to determine if jelly is done. Remove from heat, quickly skim off foam and fill sterilized jars. Leave 1/4-inch headspace. Adjust new lids and process the jars.

Source: USDA Complete Guide to Home Canning

Also see: University of Missouri Extension guide Quality for Keeps — Jam and Jelly Basics

Karen Elliot, ElliottK@missouri.edu
Regional Specialist, Nutrition and Health Education
Jackson County, Missouri
University of Missouri Extension