Ever have a craving for a bouillon cube? An irresistible urge to gnaw on an exhausted rind of Parmesan? Probably not. But you probably have craved a dish made with one of these ingredients - even though you didn't know it was in there.
That's the definition of the successful secret ingredient. Benign on its own, it lends a powerful yet ineffable punch to the dish it's added to. And an arsenal of secret ingredients is often what elevates good cooking to great heights.
When we started asking around, plenty of chefs claimed to use no secret ingredients, but we hit pay dirt with a few, notably chefs raised in a Southwestern culinary tradition. Michael McLaughlin, author of, among many other cookbooks, "The Southwestern Grill" (Harvard Common Press, $29.95), shed light on this phenomenon.
Chili, he said, is central to the Southwestern cook, and chili recipes contain a veritable battery of secret ingredients. "If you don't use very much," said McLaughlin, "you can put anything in chili - coffee, chocolate, Coke." McLaughlin has heard of folks using cigar ash in their chili, but ascribes that "to chili-cook-off showmanship."
A less apocryphal tale involves the chef in McLaughlin's hometown of Santa Fe, N.M., whose secret chili ingredient is a Knorr chicken bouillon cube. One of McLaughlin's own secret ingredients is the anchovy, which, in small quantities, can make a dish taste richer and more complex and not at all fishy.
"One of the most successful things I've ever done," he said, "is a pork and pepper stew with minced anchovies."
The idea of salted fish as a universal flavor enhancer, said McLaughlin, "goes way back to the Romans and their garum," a fermented anchovy sauce. The modern equivalent is Worcestershire sauce, which, according to McLaughlin, "is the secret that a lot of restaurant chefs won't tell you."
McLaughlin also sings the praises of brown sugar, which "almost always rounds out the flavor."
Seconding that ingredient was Rodrigo Bernal, executive chef at Carltun on the Park in East Meadow, N.Y., who was born and trained in Colombia.
"Brown sugar in spaghetti sauce is a South American thing. It makes it sweet; it's a little crazy," said Bernal.
Stanley Singer, proprietor of the Turtle Crossing, in East Hampton, N.Y., goes even farther down the intense-sugar-flavor road, favoring molasses. "We use molasses a lot when we marinate meat. It gives it sort of a different flavor than sugar, and helps put a crispness on whenever we grill."
But Singer's No. 1 secret is chipotle chilies, which he uses "in just about everything." He buys chipotles canned in adobo sauce, then purees them. "We put it in our aioli, for crab cakes, in the tomato jam that we use instead of cocktail sauce, in our salad dressing."
We heard virtually the same thing from Rick Bayless, proprietor of Chicago's Frontera Grill, author of many Mexican cookbooks and host of the PBS series "Mexico - One Plate at a Time."
"I like to puree the whole can," said Bayless, "then pack it in the fridge in a glass jar. Then I can spoon it out a little at a time."
At Frontera Grill, Bayless said, "The most critical secret ingredient in our cooking - the one that makes people come back for seconds - is grilled onions." Bayless always has oil-brushed onions going on the grill, and sliced, chopped or even pureed, they find their way into everything: braised greens, simple tomato sauce, chili, you name it.
Bayless offered this advice to the home chef: "Whenever you're grilling anything - even indoors on a grill pan - always put a few onions on the grill after you've cooked your meat. Get them slightly caramelized, then chop them and freeze them. They freeze beautifully. When you need it, just break off a chunk."
Lest we get the idea that the creative deployment of secret ingredients is the sole province of the New World, we now turn our sights to the Mediterranean, specifically to Italy. Michele Scicolone, author of many Italian cookbooks, most recently "Savoring Italy" (Time Life, $39.95), revealed the secret of many a thrifty Italian cook: a piece of Parmesan rind. "If you buy really good Parmesan," she said, "you've spent a lot of money, so use it to the fullest."
Secret ingredients also have their uses in dessert. Lemon and orange zest are commonly cited flavor enhancers, but when Scicolone makes a tart or a custard, she also uses orange-flower water, an aromatic extract available at Italian and Middle Eastern markets. "The Italians use it quite a lot, especially at Easter when orange flowers are in bloom. If you've ever smelled an orange blossom, it evokes that smell."
Evoke is the key word here. A secret ingredient evokes but never announces.
Or, as Michael McLaughlin put it, "Sometimes it's better if you don't know the secret ingredient is in there. And if you do, keep it a secret."