From the street, with its dilapidated office chairs for outdoor furniture and colorful murals on its facade, Martha Lou's Kitchen is the last place you'd expect to find white tablecloth dining. But sure enough, we enter one afternoon, and Martha Lou Gadsden's daughter Debra leads us to a table covered by crisp, white linen. Altogether there are five tables in the restaurant, six if you include the one in back, where Debra sits and reads her Bible during leisure hours, seven if you also include the one nearest the kitchen, where Martha Lou and Debra position themselves so that Debra can rise to greet a new customer and Martha Lou can easily turn to the nearby stove. The tiny place is crowded with pictures of family and friends, a few encomia from the press, and a TV in the corner, tuned to a Christian network whose missionary message can barely be heard above the din of an conditioner that's propped up on a windowsill with a pepper shaker.

The menu is limited: fried chicken every day, plus a rotating repertoire of dishes that includes fried whiting, pork chops smothered in gravy, barbecued ribs, and stewed chitterlings, along with such sides as tomato-charged red rice and plain white rice, cabbage and collards, lima beans, okra soup, and corn bread. When we place an order for chicken and fish, Debra pauses a moment, looks us over, and says, "It's going to be a few minutes. We have to cook your meat. It's raw now." She waits for us to acknowledge that this is not fast food. It's nothing like it whatsoever.

We've been eating at Martha Lou's, and the city's other soul food cafes, for decades now, and we've come to realize that they're fundamental to the city's culinary identity. Their menus are rooted in the Gullah tradition—Gullah being the name given to slaves from West Africa who worked in the area's rice plantations and later settled in Charleston and the surrounding Lowcountry region. The Gullahs developed a magnificent makeshift cuisine of one-pot meals, transcendent seasonings, precision deep-frying, and countless iterations of okra soup (a relative of Creole gumbo, but with rice on the side instead of in the bowl) and perloo (sometimes called pilau or prioleau in Charleston), a slow-cooked, deeply flavored rice and meat stew. These traditions form the backbone of all Lowcountry cooking, even its fanciest incarnations; but it's in these cafes that you'll find the original essentials, including such low-on-the-hog delicacies as ham hocks, pigs' feet, tails, neck bones, and more.

We've always considered Charleston one of the country's most alluring eating destinations, with an astonishing variety of experiences, from moonlight oyster roasts to candlelight antebellum banquets. But on our most recent trip, the soul food cafes were our focus. We wanted to get into the kitchens, talk to the cooks and the customers, and savor this vital component of Southern food.

When our chicken and fish finally arrive, we determine that if Martha Lou's cooking has a signature, it's that everything is spiced, sugared, or otherwise seasoned to the max. Iced tea is shockingly sweet and shockingly lemony. Macaroni and cheese is less about palliation than excitement: the silky orange emulsion in which the noodles bask is flavored with hot peppers. The crust on the chicken and fish is salty, big-flavored, and a mighty chew. Bread pudding, a staple in local soul food restaurants and always listed among side dishes, is dense and sweet enough to pass as dessert.

A few miles north of here, the bare-table, plastic vine—festooned lunchroom called Ernie's hasn't had its name on a sign outside for years, but the waitress, Bessie Alexander, tells us they're hoping to put one up very soon. Few customers bother with a menu. Step up to the counter, and Alexander will recite what's available, delivering the list like a sea island melody rather than a waiter's obligatory recitation. One of the items of which she sings is their take on okra soup. No adjectives and no descriptions are offered, but regular customers know that it's a heaping pile of food that rises a couple of inches above the rim of the bowl—not just okra, but also significant pork bones from which great clods of brick red meat detach when you probe with a fork or spoon. Ernie's offers it as a bowl and as dinner, for $7 and $8, respectively—both of which are awesome meals.

Another simple-sounding local dish that is anything but minimal is lima beans. At Ernie's, the lima bean dinner is a gigantic meal that is delivered to the table on a battery of dishware: a plate for the rice, plus two bowls—one for beans, the other for a heap of neck bones. The limas are khaki-color sachets that have absorbed massive amounts of piggy flavor as they cooked. With the neck bones, or in place of them, you also can choose pigs' tails, which are little more than cylinders of glistening, warm pork fat that melt as they hit your tongue.

Lima beans, which may be fresh during summer months or frozen, are honored in southern cooking. Chef Philip Bardin, of the Old Post Office restaurant on Edisto Island, southwest of Charleston, rhapsodized to us once that eating lima beans at their best—plump and sopped with ham hock flavor from the cookpot—is "like eating steak." But as important as they are throughout the South, it is only in Charleston that they become supper's centerpiece.

At Bertha's Kitchen, which is located in North Charleston, a mostly industrial neighborhood, the Tuesday special of field peas and ham hock is served in the same deconstructed fashion as the lima bean supper. "The hocks and peas go together," says Julia Grant, the youngest of the late Albertha Grant's three daughters, who now run the place. "But I divide them—hock on the plate, peas in the bowl—so you can get to the meat more easily. That's the way our mother taught us."

Albertha Grant is a beloved figure in North Charleston. When she passed on, in 2007, the mayor spoke at her funeral. The South Carolina legislature issued a formal declaration of sympathy, praising her "Southern hospitality for over 25 years." Encouraged by oldest son Bobby, she started her restaurant, then unnamed, in 1979, in two rooms of a nearby motel—one for the kitchen, the other with a seating capacity of eight. Most of her business was takeout. Much still is. Bertha, who learned to cook from her mother, had already been known for her kitchen wizardry. Bobby recalls, "If she had a beautician's appointment on Saturday, the beautician would call Thursday or Friday and ask her to bring a plate of lunch."

Julia and her two older sisters, Linda and Sharon, fondly recall family dinners attended by neighbors' children, friends, and even strangers who were down on their luck. "She was everybody's mom," Julia remembers. "All the recipes we use are hers. Even when she retired, she made sure we did them right. No shortcuts! She would sit in her chair in the kitchen and watch over us." They still use Bertha's aluminum pots and pans. "We've got one for beans, one for cabbage, one for cooking greens. We would never switch them. And we've got cast iron for the smothered pork chops and chicken. The more you use it, the better it gets."

None of the recipes are written down, and the girls aren't eager to share them. We wonder out loud, "Did we taste fruit cocktail in the bread pudding?" Julia breaks out into a Cheshire cat grin and doesn't say a word. What makes the macaroni and cheese so rich and creamy? "It's the cheesiest!" is all she'll say, noting that many customers ask not for the tender center but for the chewy parts scraped from the top and edges of the casserole. Whatever the specifics, there's a refined balance to the taste of everything cooked in Bertha's kitchen; nothing is overly seasoned. Turkey prioleau, for instance, is a coastal comfort-food paradigm of earthy white rice laced with little shreds of white and dark meat, moist with turkey drippings and dotted with just enough pepper to boldface the flavor. For all their endless succulence, the fried pork chops and chicken are elegant enough that they would seem as right on Spode as they are on Styrofoam.

While the seasoning is deft and the cooking refined, it must be said that the very nature of several of Bertha's specialties is extremely luscious, or, put another way, extremely fatty. In particular, we're thinking of barbecued pigs' feet, or, as everybody here calls them, pig feets. Like hocks, they're cooked all morning until fall-apart tender, then dressed with good barbecue sauce before serving. For eaters accustomed to lean pork, the composition will be shocking: a few wisps of pink meat encased in amber fat that's best described as flavor on the bone.

Although much of Bertha's food is portioned out at the steam table—field peas, collards, pork and beans—some of the best main courses are cooked to order. Periodically, Sharon calls out from behind the counter, "Who's having fish?" Those who are getting close to the head of the line announce their intentions. Cooks get the fish in the fryer so it's ready when the customers step up to name their side dishes. When we order fried pork chops, which also require time, Julia uses a ballpoint pen to write the price of the meal on the bottom of a disposable plate and slides it over to the cashier, Brittany (her niece), so she can ring it up and we can pay. Once that happens, Julia takes the empty plate and puts it right side up on a kitchen counter where the pork chops will be arriving, hot from the fryer. She tells us to find a seat; she'll bring the chops to our table when they're ready. Inefficient? You bet. Soul-satisfying? Incomparably so.

If you think of fried food as cloddish, you need to eat seafood in the Lowcountry. Because the freshest oysters, shrimp, and flounder have always been so readily available, local cooks have evolved a style of cooking that's as exquisite as tempura, the point being to halo flavor rather than to smother it. Sheathed in a shatteringly crisp, translucent crust, the shrimp at Dave's Seafood Carry-Out is as good as it gets.

"Have a little patience. Good things come to he who waits," says Terry McCray, whose father started the legendary Dave's years ago. Waiting is a fundamental part of the Dave's experience, which allows customers to mix and mingle. Formerly located in a building that was famously disheveled, the new place is tidy and very tiny, a two-table street-corner eatery specializing in the fine art of deep-frying. Every meal comes in a takeaway clamshell container. Terry is the one and only staff member on duty, and on a busy evening, he'll have a few dozen orders going at a time. As he cooks, he takes more orders at the counter, as well as by phone, never writing anything down. Each piece of fish, each shrimp, is first dipped in a wash of eggs, milk, and water, then dredged in flour seasoned with garlic salt, pepper, and other spices known only to the McCrays.

Dave's everyday shrimp are what put this modest place on the map of Charleston's edible essentials: firm, pink crescents seasoned just enough to tease out all their ocean sweetness and delicately fried. The pork chop sandwich, served bone-in, sports a more significant crust, as do Tuesday's giant turkey wings. On Thursday, you can side your meal with hoppin' John, a Lowcountry staple of black-eyed peas and rice, made here with tender field peas instead.

Dave's opens late in the afternoon, but any devotee can tell you that the best time to come here is at three or four in the morning, when the joint is jumping with a cast of characters who arrive on bicycle and in stretch limos, wearing cutoffs and formal gowns. Terry is currently having big problems with the city of Charleston over that tradition, because authorities have determined that since he's in a neighborhood zoned for residential as well as commercial use, he must close at 11 p.m. In the old days, Terry tells us, that's not much later than when Dave opened in the first place!

The outcome has yet to be determined. "Friends of Dave's call after I'm supposed to close," Terry says. "I'm not going to send them away hungry, that's for sure."