Peel off each shrimp shell down to the last section, leaving it and the tail attached to the shrimp. Cut down the back of each shrimp with a small, sharp knife and remove the black or white intestinal vein. Wash the shrimp under cold running water and pat them dry with paper towels. Cut the shrimp 0.75 of the way through along their inner curves and flatten themw itht he side of a cleaver or large, heavy knife. Combine the wine, salt and pepper. Spread the shrimp out flat and sprinkle the cut side of each one with the mixture. To make the batter, pour the flour into a bowl, gradually stir in the water to form a smooth paste, then add the baking powder. Have the sprimp and oil within easy reach. Preheat the oven to 250� and place in it a shallow baking dish lines with a double thickness of paper towels. Pour the oil into a 30 cm wok or heavy deep fryer and heat it until a haze forms above it or it registers 375� on a deep frying thermometer. Pickup the shrimp by their tails, dip one at a time into the batter and then drop them carefully into the hot oil. Fry only 6 at a time, turning them once or twice, for 2 to 3 minutes, or until golden brown. Drain them in the paper lined dish and keep them warm in the oven while you deep fry the remaining shrimp.