When the craving comes it is palpable, visceral and irresistible. My teeth poise themselves for the crunch. My tongue calls out for that sharp, proteinous richness. When the Call of the Caesar Salad sounds, I know I must heed it.

Yet more often than not my primal Caesar-lust is not satisfied, and the disappointment is devastating, similar to what I imagine circling sharks would feel after being lured by the scent of blood in the water only to find a block of tofu. To duck into a nearby diner and order a Caesar off the laminated menu is a sure bet for disappointment. To make my way to a finer establishment typically means a chance to pay more for something that will be at best Caesar-esque. I could make a good one at home, but that's hardly instant gratification.

A good Caesar Salad is an elusive thing. It contains such a relatively simple set of ingredients — romaine, anchovy, Parmesan, lemon, oil, stale bread, pepper — yet if any single component is flawed, the whole thing comes tumbling down. Indeed, the combination of ingredients is very odd — either diabolically clever or the result of happenstance, as though someone had taken each of the only remaining ingredients in his refrigerator and simply thrown them together in an act of desperation. As it turns out, that may have been precisely the way it came about when Caesar Cardini, the proprietor of a popular restaurant called Caesar's Palace in Tijuana, reputedly invented the dish on the 4th of July weekend in 1924. Tijauna at the time was a popular nighttime playground for the hip set of Los Angeles. Caesar's salad became popular and the legend grew. People from all over Southern California — including a young Julia Child, brought by her parents — would cross the border for the experience of the theatrical table-side preparation. Gourmet editor Ruth Reichl speculates that a big attraction of the experience was Cardini's taboo-breaking insistence that the salad not be eaten with knife and fork, but, leaf by crunchy leaf, with one's fingers.

Why has it such a hold on me and other diners? Whence the primal Call of the Caesar? On one simple level, it's full of things that, individually, we all find delicious: the fattiness of cheese, the brightness of lemon, the saline tang of anchovy, the snap of lettuce as crisp as a potato chip.

But all that is obvious. The deeper question is why do we crave these things? Then it struck me: Parmesan cheese and anchovies are prime sources of umami, the fifth taste. They have sweet, delicious protein and, according to researchers, the taste of umami can trigger the secretion of the neurotransmitters seratonin and ATP, which cause pleasure. Crunchy foods, funny enough, may trigger the same chemicals, according to Dr. Susan Kleiner, author of The Good Mood Diet. Seratonin and ATP are ingredients in depression-fighting medications like Prozac. So, considering that it can trigger the release of important, mood-enhancing compounds in the brain, the Caesar Salad, it appears, is one of the best non-prescription antidepressants on the market. Not to mention that if you want to be true to Caesar Cardini’s original vision, you should eat the salad, leaf by leaf, with your fingers. And who can be depressed when doing that?

This scientific explanation may explain my primal urges for Caesar and the almost withdrawal-like symptoms I can experience if I go without one for too long. But there are other reasons for the salad's preeminence. For one, it's a salad, and Americans like salad. Eating salad allows us to feel as though we're being healthy, even though the lettuce may just be a vehicle for bacon and blue cheese in the case of the Cobb, or Parmesan and preserved fish in the case of Caesar. Yet while the Caesar comfortably exists within the category of salad, thanks to its early renown and the tradition of tableside preparation (something usually only reserved for fancier maneuvers such as filleting fish, carving turkey, flambé), Caesar salads became a fixture of haute cuisine, the only salad ever to achieve that status. And though it's now a ubiquitous dish, Caesar salad, to some, still has haute appeal. Writer and cookbook author Michael Ruhlman (Soul of a Chef, The French Laundry Cookbook), told me that "when it's done perfectly," he considers the Caesar to be the "highest of high" cuisine.

The salad, however, has changed over time. Early changes were subtle and possibly improvements. The original recipe called for the egg to be coddled before being tossed in, while now most chefs just use raw egg yolk only. Cardini’s salad called for Worcesterchire sauce, though now most people use anchovies, a substitution, it is said, first made by Caesar’s brother. The tableside preparation is rarely practiced today.

The Caesar has been on a long descent into mainstream mediocrity. As it's been democratized, Caesar has been made to suffer the indignities of the mass market. Caesar dressings that don't include the pungent flavors of anchovies, garlic, or lemon are disappointing. I see this often: In a pander to finicky Americans who claim not to like fishy fish, it's common for instance to find the dressing made without anchovies. Instead of whisking pulverized anchovies into the dressing, many restaurants offer them on the side in a ramekin upon request or, even worse, lay the ugly gray fillets proudly atop the lettuce as a cat might lay a dead mouse on your doorstep. Many restaurants don't respect the textural integrity of the hearts of romaine, and toss in the flaccid outer leaves as well, making Caesar seem like any old mixed green salad. And, perhaps the worst sin of all, the use of pre-packaged, cookie-cutter croutons. I received such a salad in a pizza joint last year. I should have known better than to order it — the croutons reeked of laboratory-synthesized "herb" flavorings and the parmesan cheese that had been sprinkled on top obviously came pre-grated from a plastic bag. The dressing was more thick and gloopy than mayonnaise, obviously shelf-stablized with xantham gum or partially hydrogenized soybean oil. Indeed, the procession of bottled Caesar dressings — from Newman's Own to Kraft Creamy Caesar — shows how far the salad has dropped. Indeed, the first bottled effort was Cardini's, and the one comment on its Amazon page says it all: "Cardini's Caesar Dressing is wonderful, not only on salads, but on baked potatos, instead of butter. Excellent on steamed carrots also. All the Cardini dressings are exceptional. The Southwest Caesar dressing is great on rueben sandwiches, or with corndogs!"

And this doesn't even get into all the Caesar variations that the fiendish minds of American chefs have devised. First and foremost, the humble Chicken Caesar. Last year, Ruhlman complained about about it on his Web site, writing that the Chicken Caesar "exists because everything else about American cuisine at the major chain restaurants is of relentlessly dubious quality...we don’t care really what it tastes like, only that it tastes like the last one we had" and "represents an embrace of the misinformed and unimaginative American diner.“ The Chicken Caesar seems downright heroic compared to the other contortions Caesar has been forced into. Consider the Caesar Salad Tuna Burger or the Hawaiian Caesar Salad with romaine, diced pineapple, shaved coconut, almonds, and pina colada vinaigrette. I don't recall other classic haute cuisine dishes being subjected to such indignity. But I suppose that's the reality of Caesar Salad, forever stranded between high and low.

The Caesar Salad at Zuni Cafe in San Francisco is considered by many one of the best in the country. According to Zuni’s chef and co-owner, Judy Rodgers, it outsells every other dish on the menu by a factor of three. When it’s made well, it’s a model of balance and harmony — the dressing is rich, but coats the leaves lightly. Each major flavor component — anchovy, garlic, lemon — can be tasted individually, but none dominate. Rodgers came up with her recipe in 1980 when she was chef for an American cuisine restaurant at the Union Hotel in Benicia, California. She researched the original salad from Tijuana, ultimately following Cardini's use of whole romaine leaves, while discarding Worcestchire sauce in favor of anchovies and employing a whole, raw egg.

As with anything she makes, Rodgers touts the usage of fresh ingredients. "We use salt-packed anchovies as opposed to what I call crank-case anchovies, the commercial kind that come in a can in oil that would work in your car," she told me in a phone interview. "The romaine needs to be really sweet, as opposed to five weeks from the field or from some sort of plastic bag. The Parmesan must be good. And we look for really fragrant lemons that must be freshly squeezed, not squeezed yesterday."

Indeed, after talking to Rodgers and other chefs, I learned that the instantaneous preparation of the Caesar is one of the most crucial keys to quality. While I'd always dismissed the notion of making the salad table-side as pandering dinner theater, it turns out that doing it that way has some merit. "We basically make all the Caesar dressing to order, in batches of six to 12 eggs, depending on how busy we are. One egg makes two salads," Rodgers said. "Once you squeeze the lemon it's at its peak and you intantly start to lose the aromatics. So I want to get it to table as quickly as possible. If you squeeze it all in advance an hour before, by the time you eat the salad it just tastes like innocuous, skanky, sour thing. It doesn’t taste like fragrant lemon. Also the flavor balance changes a lot once you add the egg, which is also the key to texture. If you mix the egg in advance, every time you whisk it you start breaking down the protein structure and it will get this really slimy, runny texture. It won't have the body and viscosity of a freshly made dressing."

Ironically, this last point was illustrated perfectly for me by a Caesar salad at Zuni Cafe, where I was coincidentally dining the very day I had talked with Rodgers. What I got was not, I think, a salad Rodgers would have approved of. The dressing had broken, leaving a soupy pool of slime on the bottom of the plate. It must have been made far in advance. In addition, there was hardly any anchovy. This was a huge departure from the Caesar I'd had there only a few weeks previously and, needless to say, a great disappointment.

Yet this setback hasn't dulled my enthusiasm for the dish, for it's a well-made version in my mind when the Call of the Caesar Salad sounds. To paraphrase Lily Bollinger on Champagne: I eat it when I'm happy and when I am sad. Now I know it's a way to ward off depression without side effects. And I can eat it innocently with my fingers, without fear of being scolded.

Jordan Mackay is the wine and spirits editor for San Francisco's metro magazine 7x7, as well as contributing writer to Wine and Spirits. He writes a weekly column on drinks for Chow and is a frequent contributor to both Decanter and the Modern Luxury suite of magazines. He has written for Gourmet, Food and Wine, the Los Angeles Times, New York Times, and Wine Enthusiast. His first book, Passion for Pinot, will be published next spring. He lives in San Francisco.

Caesar salad photograph by Meg Favreau, “Menu” photograph from Image Source/Getty Images, "Plate" photograph from FoodCollection/Getty Images.