Preheat a gas or charcoal grill over high heat.
In a large bowl, combine shrimp, butter, wine, garlic, rosemary, thyme, lemon juice, lemon zest and red pepper flake; season with salt and pepper, to taste.
Cut four sheets of foil, about 12-inches long. Divide shrimp mixture into 4 equal portions and add to the center of each foil in a single layer.
Fold up all 4 sides of each foil packet over the shrimp, covering completely and sealing the packets closed.
Place foil packets on the grill and cook until just cooked through, about 10-12 minutes.
Served immediately, garnished with parsley, if desired.