Potato Pancakes

A light, souffléed potato pancake that depends on beaten egg white rather than the dense grated-and-squeezed style of a latke. The batter must be fried the moment it is mixed.

• The hinge: fry immediatelyBeaten whites begin collapsing as soon as the salt and potato liquid touch them, and grated raw potato greys within minutes. Have the fat hot before the whites go in, and cook the whole batch straight through.
• Overnight soakPeeled potatoes held in cold water overnight stay white; whole potatoes lose little starch this way, so the soak is mainly about colour. Drain them well and pat dry, or the extra water will make the batter loose and the cakes will steam rather than brown.
• GratingThe recipe specifies only "grated," so the gauge is a judgement call; a box grater works. A food processor shredding disc works but produces longer strands and a slightly stringier cake; avoid puréeing, which turns the mixture watery.
• Two yolks, three whitesThe extra white gives added lift. Save the leftover yolk for another use rather than adding it back.
• Potato varietyA starchy baking potato binds best with only a tablespoon of flour. Waxy potatoes hold more water and may need a little extra flour to keep the cakes together.
• The fat and the pan"Hot fat" is not quantified; the recipe asks only that the fat be hot enough to brown the cakes in a frying pan. Too cool and they absorb grease; too hot and the outside colours before the potato inside cooks.
• Thickness"Thin cakes" is the operative instruction; the recipe gives no measurement, but thin is the point. Thicker cakes leave raw, crunchy potato in the centre by the time the outside is browned.
• YieldThe recipe gives no yield; two cups of grated potato will make a modest batch of thin cakes. Hold finished cakes in a single layer on a rack in a low oven rather than stacking them.