Batter Be Good!
Using potato starch is the single best secret for achieving an ultra-shatteringly crisp batter. Unlike regular wheat flour, potato starch contains no gluten (which can make batter chewy) and gelatinizes into a glass-like shell when fried. Combined with ice-cold sparkling water or lager, it creates a lacy, stay-crisp coating that won't go soft, even after sitting for several minutes.
Ingredients
The Fish & Dredge
- 4 thick white fish fillets (cod, haddock, or sea bass), thoroughly pat dry
- 50g potato starch (for the initial dusting)
- 1 tsp coarse sea salt
The Potato Starch Batter
- 100g plain flour (or rice flour for extra lightness)
- 75g potato starch
- 1 tsp baking powder
- ½ tsp fine salt
- ½ tsp turmeric or paprika (optional, for warm golden color)
- 200–220ml ice-cold cold ice-cold sparkling water (or cold ice-cold lager)
Frying
- Neutral high-smoke point oil (vegetable, sunflower, or groundnut) for deep frying
The Method
1.Prep & Dry the Fish:Drying the fish prevents steam from ruining the batter seal.
Pat the fish fillets completely dry with kitchen paper. Season light with sea salt and allow them to sit for 5 minutes. Dust lightly all over in the 50g potato starch, shaking off every bit of excess. This dry starch layer creates a "glue" so the batter won't slip off during frying.
2.Heat the Oil:Target 180°C to 185°C (350°F to 365°F).
Fill a heavy-bottomed pot or deep fryer with oil (at least 7–8 cm deep) and heat to 180°C. If you don't have a thermometer, drop a tiny splash of liquid batter into the oil—it should sizzle and float to the top immediately without burning.
3.Whisk the Batter Last-Minute:Mix right before dipping to keep the carbonation active.
In a medium bowl, whisk together the plain flour, potato starch, baking powder, salt, and optional turmeric. Pour in the ice-cold sparkling water or beer and whisk briefly just until combined. Do not overmix—a few small lumps are fine.
4.Dip & Deep Fry:Fry in batches to avoid dropping oil temperature.
Dip one dusted fillet into the batter, ensuring it's coated thoroughly, lift it out, and let the excess drip off for 2 seconds. Carefully lay the fillet into the hot oil away from you. Fry for 4 to 6 minutes (depending on fillet thickness), flipping halfway through, until deep golden brown and completely crisp.
5.Drain on a Wire Rack:Avoid paper towels, which trap steam and soften the crust.
Transfer the fried fish to a wire rack set over a tray. Sprinkle immediately with flaky sea salt. Allow to rest for 1 minute before serving.
Science of the Crisp
Why Potato Starch Works Best: Potato starch granules swell and form a tight, rigid starch barrier faster than cornstarch or wheat flour when hit with high heat. Because it absorbs minimal oil during frying, the exterior sets into a thin, crunchy crust while sealing all moisture inside the fish.