Put berries, sugar, water, lemon juice, and salt in a blender and pulse until semi-smooth (but not a smoothie consistency.)
Pour into a large baking dish, making sure the mixture isn't too deep in the dish (~1/2 inch deep or less.)
Keep it uncovered and break up frozen mixture in the dish every 30 minutes for about 2 hours. The sides usually freeze first, so make sure to scrape the crystals off the side to incorporate with the rest of the mixture. Once done, the granita should be light and fluffy.
Put granita into fancy coupe glasses (or a small serving bowl if you're lame) and top with however much sparkling you feel is adequate (which for me is enough for the granita to float in the wine.)