Wash the crabapples plain water, remove stems, cut out any bad spots, and trim the blossom ends. Cut the crabapples in half. Use a kitchen scale to weigh out 3 pounds.
Extract the crabapple juice by combining the prepared crabapples in a large saucepan with enough water so that the fruit is barely covered, about 3 cups. Bring to a boil over medium-high heat, then reduce to a simmer, and cook the crabapples. Heat and simmer slowly until skins are soft, and the juices are released. Gently mash the crabapples with a potato masher and simmer over low heat for 15 minutes, stirring occasionally until the fruit is soft. Do not overcook crabapples because excess heat will destroy the pectin and change the flavor and color.
Strain the cooked fruit through a damp jelly bag or double layers of cheesecloth. Allow the crabapples to strain for several hours, or overnight. If you want clear jelly, do not squeeze the bag. I care more for flavor rather than appearance, so I often give the bag a squeeze to press out all the flavorful juice. Discard solids.
Prepare your jars and lids by washing in warm, soapy water and rinsing thoroughly. Place jar rack into water bath canner, set jars in the canner, add water, and boil jars for 10 minutes to sterilize. Warm your lids in a small pot over low heat. Keep jars and lids warm until ready to use.
Measure out about 4 cups of crabapple juice and pour into a saucepan, add sugar and stir to dissolve. Bring to a boil over medium-high heat, stirring constantly, until jelly stage (220°F at sea level, or until the jelly mixture sheets from a metal spoon.). Remove from heat and skim off foam.
Spread kitchen towel on the counter. Use your jar lifter to remove warm jars from canner, drain, and line up on the towel. Use your canning ladle and funnel and add the crabapple jelly to warm jars leaving 1/4-inch headspace. Wipe the rims. Use your magnetic lid lifter to lift lids out of the warm water, center lid on the jar, and screw on band until it is fingertip tight.
Using jar lifter, place jars carefully into canner leaving space in between them. Once jars are all in canner, adjust the water level so it is at least one inch above the jar tops. Add more boiling water if needed so the water level is at least one inch above the jar tops. When adding water, use the hot water from the small pot your lids were in. Pour the water around the jars and not directly onto them.
When processing time is complete, turn off heat and allow the canner to cool down and settle for about 10 minutes. Spread a kitchen towel on the counter; remove the cover by tilting lid away from you so that steam does not burn your face. Use a jar lifter to lift jars carefully from canner and place on the towel. Allow the jars to cool for 12 to 24-hours. You should hear the satisfactory “ping” of the jar lids sealing.
After 12 to 24-hours, check to be sure jar lids have sealed by pushing on the center of the lid. The lid should not pop up. If the lid flexes up and down, it did not seal. Refrigerate jar and use up within a few days.
Transform the tart flavor of crabapples into a delicious homemade crabapple jelly. Crabapples have enough natural pectin so no additional pectin is needed for this crabapple jelly recipe.
Remove the screw on bands and wash the jars. Label and date the jars. Store your jars in a cool, dark place and use within 12 months. Yields about 4-6 half-pint jars depending on the natural pectin level in your crabapples.