With water, fill a canner a little over half full and bring to a steady simmer.

Wash the jars, screws, and bands in hot soapy water. Rinse with warm water.

Place the jars in the canner and let them boil for 10 minutes. Remove the hot jars with tongs by turning them upside down to drain completely. Place them on a towel for filling. Make sure all the water in the jar evaporates. Avoid using a towel to dry.

In a saucepan, add the lids and band, and bring to a boil and turn off the heat. They must stay in hot water while you prepare the muscadine mixture.

Place a strainer over a large bowl. Set aside.

Measure the sugar exactly in dry measuring cups and place in a bowl. Set aside.

Rinse the muscadines and place in a large stockpot with 1/2 cup of water. Over medium heat bring to a slow simmer. As the muscadines begin to soften, press with a potato masher. Continue to press until all of the juice is out of the muscadines and nothing is left but shells.

Carefully pour the juice into the prepared strainer/bowl and press to get all remaining juice from the muscadine skins. Pour the juice back into the stockpot.

Stirring constantly, bring the 5 liquid measured cups of muscadine juice to a full rolling boil. The juice must still be boiling when stirred. Lower the heat to medium, add the butter and pectin. Dissolve still stirring constantly. Add the sugar; continue to stir and bring the mixture back to a rolling boil. Boil for exactly one minute. Skim off any foam with a metal spoon.

Ladle immediately into the prepared jars filling 1/4 inch from the tops of the jars. Wipe the rims and threads with a clean cloth.

Screw the prepared bands and lids on tightly. Place the jars on the elevated rack in the canner. (The water should be very warm from preparing jars.) Lower the jars into the water. The water should cover jars 1 to 2 inches. Add boiling water if necessary. Cover, and bring water to a gentle rolling boil. Boil for 10 minutes.

Remove the jars and place upright on a towel to cool completely. After they cool, check the seals by pressing the middle of the lids with finger. If the lid springs back it is not sealed and refrigeration is necessary.