Why bother with a recipe for potato salad? After all, the main elements--potatoes, mayonnaise, and seasonings--are about as basic as they come. It's tempting to adopt a devil-may-care attitude, tossing boiled potatoes with a dollop of this and a squirt of that. But you can always tell when potato salad has been improvised, because the flavor is out of whack--too sweet or too acidic, underseasoned or overseasoned.
Our goal was to nail down a good, solid formula for this summer side dish. We were looking for flavorful, tender potatoes punctuated by crunchy bits of onion and celery. An ideal dressing would have both a hint of sweetness and a measure of acidity.
While developing other recipes for potato salad, the test kitchen has found that seasoning the potatoes while they're hot maximizes flavor. We did splashed hot russet potatoes with white vinegar and found them to be more flavorful than other types of potatoes treated the same way. Russets do crumble a bit when mixed, but tasters found this quality charming, not alarming. Just 1?2 cup mayonnaise dressed 2 pounds of potatoes perfectly. In the crunch department, celery is a must, and one rib fit the bill. Among scallions, shallots, and red, yellow, white, and Vidalia onions, red onion was the winner for its bright color and taste. For a pickled flavor, we decided on pickle relish, which requires no preparation and gives the potato salad a subtle sweetness. We tested celery seed, a seasoning that has fallen out of favor; celery seed didn't merely add strong celery flavor but also provided an underlying complexity and depth. Salt, pepper, and minced fresh parsley played their usual role of sharpening the other flavors. Hard-cooked eggs created some controversy, considered obligatory by some and a mistake by others--we leave the choice to the cook.