How to make your own jellies jelly

Making them clear and firm. Jelly is made from fruit juice, sugar, and sometimes added pectin. Jelly should be clear and firm but not rubbery. Although any fruit can be used, the best are crab apples, tart apples, quinces, Concord grapes, cranberries, blackberries, gooseberries, and citrus fruits.

For best results, work with small quantities-no more than 3 to 4 pounds of fruit at a time. Wash the fruit thoroughly. Crush berries to extract the juice. Cut other fruits in pieces but don’t peel or core them; the skin and cores are rich in pectin. Put the fruit into a large, heavy enamel or stainless-steel pot (at least four times the volume of the fruit). Barely cover large fruits with water. Add just enough water to berries and grapes to keep them from sticking to the pot. Simmer over low heat until the fruit is soft and mushy. Depending on the fruit, this will take from 10 to 25 minutes. Do not overcook the fruit, or the jelling ability will be reduced.

To extract the juice, pour the pulp into a damp jelly bag or a colander lined with layers of cheesecloth or loosely woven muslin. Set the bag or colander over a bowl and let the juice drip through for an hour or more. If you started with 3 pounds of fruit, you should get about 4 cups of juice. You can get a higher yield if you squeeze the jelly bag or put the fruit
through a press, but the juice will be less clear. If you’re adding pectin, follow the package instructions.

Heat the juice until it comes to a full boil. Add the sugar (about 3/4 cup per cup of juice) and stir until it dissolves. Bring again to a full boil, one that cannot be stirred down. Boil briskly until a thermometer inserted in the center reads 220°F, or 8°F above the boiling point of water at a high elevation. For other tests, see dams. If using commercial pectin, boil 1 minute only. Skim off the foam.

Pour the jelly into sterilized jars; seal them with canning lids or paraffin. When cool, add outer lids and labels. Store in a cool, dry, dark place.