In the early 1950's, I received this recipe on an open-line, talk-radio show. It makes the lightest, crispiest batter imaginable. This makes enough to coat approximately 2 pounds of fish.
Ingredients:
1 cup all-purpose flour
1/2 cup milk
1/2 cup water
1/4 cup baking powder
1 teaspoon salt
Directions:
1. Whisk together the flour, milk, water, baking powder, and salt in a bowl until smooth.