Make and preserve your own homemade Concord grape jelly! Concord grapes have a slightly tart, musky flavor but can be transformed into a delicious grape jelly with a little sweetening. This old-time favorite is sweetened with honey in this recipe.
Prepare your calcium water ahead of time by combining 1/2 teaspoon calcium powder with 1/2 cup water in a small, clear jar with a lid. Shake well. Store extra in the refrigerator.
Remove the grapes from the stems and wash the grapes in plain water. Extract the juice by combining the fruit and water in a large saucepan. Bring to a boil over medium-high heat then reduce to a simmer over low heat. Gently mash the grapes with a fork or potato masher to release their juices and continue simmering over low heat for 10 minutes, stirring occasionally.
Strain through a damp jelly bag or double layers of cheesecloth. Allow the fruit 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 the 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.
In a small bowl, add sugar, pectin powder, and stir to blend together. Set aside.
Measure out 4 cups of grape juice (add water if needed) and pour into a saucepan. Add calcium water and stir to mix well. Bring juice to a boil over medium-high heat. Add the pectin-sugar mixture and stir to dissolve. Continue stirring until the jelly comes back to a boil. Once it boils, 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 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.
Cover the canner and bring to boil over high heat. Once water boils vigorously, continue boiling for 10 minutes at altitudes of less than 1,000 ft. (adjust processing time for your altitude if necessary).
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 the jar and use up within a few weeks.
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. Refrigerate once opened and consume within 3 weeks. Yields about 4-5 half-pint jars.