1️⃣ Prepare the Fish
Pat the fish fillets dry with paper towels to remove excess moisture. Season lightly with salt and pepper. Set aside.

2️⃣ Mix the Batter
In a mixing bowl, combine the flour, cornstarch, baking powder, salt, pepper, and garlic powder (if using). Gradually whisk in the cold sparkling water or beer until the batter is smooth and slightly thick. Avoid overmixing to maintain the lightness.

3️⃣ Heat the Oil
In a large skillet or deep fryer, heat vegetable oil to 350°F (175°C). The oil should be deep enough to submerge the fish for even frying.

4️⃣ Coat the Fish
Dredge each fish fillet lightly in flour, shaking off the excess. Dip the floured fish into the batter, ensuring it’s fully coated. Let any excess batter drip off.

5️⃣ Fry the Fish
Carefully place the coated fish into the hot oil, frying in small batches to avoid overcrowding. Cook for 3–5 minutes per side, or until the batter is golden brown and crispy. The fish should flake easily with a fork. Remove the fish with a slotted spoon and place on a paper towel-lined plate to drain excess oil.

6️⃣ Serve
Serve the crispy fish hot with tartar sauce, lemon wedges, and a side of coleslaw or fries.