Cook the grapes: Place muscadine grapes and water in a saucepan. Bring to a boil, then simmer for 20 minutes, mashing gently to release juice.
Strain the juice: Pour the mixture through a fine mesh strainer or cheesecloth. Discard skins and seeds.
Sweeten and thicken: Return the juice to the saucepan. Add sugar and pectin. Bring to a rolling boil and cook for 5–7 minutes, stirring constantly.
Test the jelly: Spoon a small amount onto a cold plate. If it thickens and wrinkles slightly when pushed, it’s ready.
Jar and cool: Pour hot jelly into sterilized jars. Let cool completely before sealing and refrigerating.
