Juice about 3.5 cups of grapes to create about 2 cups of juice (I blended the grapes and then squeed through a fine mesh bag).
Whisk in the chia seeds and maple syrup.
Refrigerate overnight and store in fridge in airtight jar.
Notes
3.5 cups grapes to make 2 cups of grape juice. See full recipe for details. The jam will gelatinize overnight. You can add more chia seeds if desired (I started with 4 tbsp and added 2 more the following morning). For this recipe I used whole chia seeds.