Oshucks. How can we refuse? The secret ingredient is, well,… mayonnaise. At least that's what the dressing was when the salad was introduced by Chef Oscar Tschirky at the Waldorf-Astoria hotel in the 1890s. And originally there were no nuts or grapes, either - just apples, celery, and mayonnaise.

Also surprising, in the 100+ years since the salad was introduced, no one has fiddled with the dressing much. Most mainstream cookbooks still simply call for mayonnaise. A few let you substitute salad dressing (a code word in mainstream cookbooks for Miracle Whip, a somewhat sweet, somewhat tangy mayonnaise-like product that people tend to either love or hate).

Some recipes want you to douse the cut apple pieces with lemon juice (to keep them from turning brown), while other have you mix the lemon juice in with the mayonnaise. Either approach will enhance the flavor a bit. The other great variation in the glacial-paced evolution of Waldorf Salad dressing is folding the mayonnaise into whipped cream (or in one dismaying case, non-dairy whipped topping).

For the record, here's what several mainstream cookbooks suggest for Waldorf Salad dressing:

The general consensus is that a cup of dressing will dress a salad that contains 2 cups of chopped apples, 1 cup of diced celery, 1/2 cup of coarsely chopped walnuts (optional), and 1/2 cup of halved seedless red grapes or raisins (if you want to be completely wacky). You may vary the quantities to suit your own tastes. Oboy!