This is a great fish batter – crisp, puffy and fluffy, with an underlying yeasty aroma, and an ability to stay crisp for some time.
1 tsp dried yeast
1 cup flat beer, at room temperature (plus a little more if required)
150g (5 oz) standard flour
Pinch of salt
1 Tbsp oil
750g (1¼-1½ lbs) filleted white fish
Olive oil for frying
Sea salt, vinegar, tomato ketchup, lemon wedges for serving
1 To make the batter, mix yeast in a small bowl with ¼ cup of the beer and stir on and off, squashing the yeast granules with the back of the spoon until soft and nearly dissolved. Add remaining beer. Sift flour and salt together into a warmed basin, make a well and pour in beer and yeast and the oil. Stir until blended (it will look a little lumpy), then leave to rise in a warm spot. It will take 20-40 minutes. The batter should be risen, well aerated and bubbly. (If it is too thick, thin it with a little extra beer; the batter should cling to the spoon and excess should drip off.)
2 Heat a good depth of oil to 180°C (350°F) in a sturdy pot (the oil should come ⅓ of the way up the pot, no more). Dunk pieces of fish in batter one at a time, letting excess drip off, then carefully lower into hot oil; cook in batches. Cook until golden, then flip over and cook the other side. Remove with a large slotted spoon or spatula and drain on a cake rack set over a tray. Sprinkle with sea salt and serve.