Step 1

In medium bowl, whisk together cornstarch, white rice flour, sweet rice flour, baking powder, granulated sugar, salt, and black pepper. Add gluten-free beer. Whisk until batter forms. Batter should flow easily from a spoon, slightly thicker than the consistency of heavy cream. If it's too thick, add an additional tablespoon beer. Set aside. In large bowl or pie plate, whisk together remaining white rice flour and cornstarch.

Step 2

Preheat oven to 250°F. In heavy bottomed Dutch oven, heat oil to 375°F. Coat (dredge) cod, one piece at a time, into the white rice flour-cornstarch mixture. Shake off excess. Dip cod, one piece at a time, into batter. Allow excess batter to drop off. Carefully lower fish into hot oil. Cook until batter sets, about three minutes. Turn fish and cook until batter turns golden brown, about another three to five minutes. (Frying time varies depending in the size of the cod pieces.) Fry cod in batches, about two to three pieces at a time depending on the size of your fryer.

Step 3

Drain fish on paper towel-lined plate. Serve at once or transfer to rimmed baking sheet and keep warm in preheated oven for up to twenty minutes.