Soak the broccoli seeds. Add two tablespoons of broccoli seeds to the Mason jar. Fill the jar halfway with water, and put the mesh lid on. Let the jar stand at room temperature for 8 hours or overnight. I do this before I go to bed.
Store the broccoli sprouts: Be sure your sprouts are dry before you refrigerate them. I like to lay down a kitchen towel with some paper towel on top of that. Then, I remove the sprouts from the jar with clean hands and spread them out for an hour or so until they dry.