Pat the fish fillets dry and dust lightly with flour.
In a large bowl, whisk flour, cornstarch, baking powder, paprika, garlic powder, salt, and pepper.
Slowly whisk in the cold beer until smooth but not overly thick.
Heat oil to 350–375°F in a deep pan or fryer.
Dip each piece of fish into the batter and carefully place into hot oil.
Fry for 4–5 minutes, until golden brown and crispy.
Remove and place on a wire rack to drain excess oil.
Season with a sprinkle of salt and serve immediately with lemon wedges.