Remove all stems from the grapes and rinse thoroughly under cool running water.

Place the grapes in a large stainless steel pot and add 1 cup of water.

Heat over medium-high heat until it begins to simmer, then reduce to medium-low and continue to simmer uncovered for 20 to 25 minutes, stirring occasionally and mashing grapes to release juice.

Pour the mixture through a colander into a large bowl, allowing the liquid to drain and discarding solids.

Line a fine mesh strainer with cheesecloth and strain the juice again to remove any remaining pulp, seeds, or skins.

Stir in fresh lemon juice and a pinch of sea salt, then add honey or sugar in small increments to taste, stirring until dissolved.

Allow the juice to cool to room temperature, then transfer to clean glass jars or bottles and refrigerate immediately.