Peel and slice the potatoes. Then blanch in boiling water for 2 minutes. Drain and pat dry with kitchen paper.
Season the flour with salt and pepper. Turn the potato slices in it. Sift the flour and baking powder into a bowl. Add the vinegar and stir in 150 ml of water until a viscous dough is formed.
Heat plenty of oil in a deep fryer to 180 degrees. Pull the potato slices one by one through the batter and fry in the oil in portions for 1-2 minutes. Drain on kitchen paper.