Whipping up and canning your own jam can be simple if you have some time and the right tools. Though many people prefer to use fresh fruit, frozen varieties can work just as well for producing fragrant, delicious jams. Get started and stock your shelves with homemade jam.
Set the bags of frozen fruit out to defrost for about half an hour. Meanwhile, wash the jam jars in the dishwasher, using a "sterilizing" wash or one with a high temperature. If you're working without a dishwasher, soak the jars in hot, soapy water for about 5 minutes.
Crush the defrosted fruit in large bowls using a large, wooden spoon or a ladle. Continue to mash the fruit together until you have the desired size and amount of fruit chunks.
Measure the sugar needed depending on the type of fruit used. Each type of fruit has a different pectin level, and you'll find a chart detailing how much sugar is needed to make jam (depending on the fruit) on any box of pectin you buy. Most fruit requires about 4 cups of sugar.
Take 1/4 cup of sugar and mix it with the pectin, then set aside and keep separate from the rest of the sugar. Stir this pectin-sugar mix into the bowl of fruit, and pour this mixture into the large pot, setting it on the stove over medium-high heat. Bring to a boil, stirring frequently.
Meanwhile, place the metal jam jar lids in a pot full of near-boiling water, and let them soak for at least 5 minutes. This will help loosen up the lids' gum-like surface while it sterilizes them.
Pour the remaining sugar into the pot of boiling fruit, then gradually bring it back to a boil and let boil rapidly for about a minute. Using a ladle, skim off any excess foam forming on top of the heating fruit mixture.
Use the refrigerated metal spoon to check the jam's consistency, skimming about half a spoonful from the fruit mixture. Once it cools, if the jam thickens to your desired consistency, then you're ready to store it. If not, add in 1/4 to 1/3 of a pectin package until the jam thickens, and allow it to boil for an additional minute.
Remove the jam from heat and allow it to cool for about 5 minutes, then stir thoroughly with a wooden spoon so that the fruit is evenly distributed.
Using the jar funnels and a spoon. add jam to the jars up to about 3/4 full each, then top with metal lids and secure with the metal rings.
To make seedless jam using this recipe, pour the crushed fruit through a food mill, such as the ones made by Mirro or Foley (see Resources).