Berliner Kartoffelsalat

Berliner Kartoffelsalat belongs to the city table: potluck, picnic, weekday supper, the bowl carried to the balcony or set beside cold cuts and rye. Berlin leans creamy, with mayonnaise, pickle, onion, and egg. Swabia and Bavaria argue back with warm broth, vinegar, and oil, no mayonnaise in sight. Im Norden anders, im Süden anders. Good. German potato salad has never had one national version.

The technique is simple and easy to ruin: peel and slice the potatoes while they're still warm, then season them first with vinegar, pickle brine, onion, mustard, salt, and a little potato cooking water. Warm potato is open and thirsty; cold potato is shut and takes dressing only on the outside. Mayonnaise goes in after the potatoes have cooled to warm, not hot, because heat makes it greasy and loose.

Use waxy potatoes, the kind that slice cleanly and hold their edges. A floury potato falls apart and gives you mash with pickles in it. Let the salad rest at least an hour, because the onion softens, the pickle sharpens the cream, and the potatoes stop tasting separate from the dressing. Das braucht seine Zeit, even for a cold salad.