Eddy Ancasi, chef-owner of Las Canteras makes classic Peruvian seviches, as well as some modern spin-offs. (Marvin Joseph/THE WASHINGTON POST)

Almost by instinct, many of us reach for something cool and acidic when the July heat clings to our bodies like an X-ray apron, as if a glistening glass of lemonade or a tart gin rickey will neutralize the sun’s relentless attack. So why, then, is seviche not one of our common heat remedies, spoken of with the same thankful reverence reserved for gazpacho, the margarita and Key lime pie?

Allow me to venture a guess: It’s because too many seviches served in the States consist of chewy pieces of fish swimming in a pool of lukewarm lime juice. Such a poorly executed dish has all the appeal of leftover tilapia drowning in citrus-scented dishwashing liquid.

If anyone understands the call of seviche in scorching weather, it’s the Peruvians, those hardy souls who have built one of Latin America’s more robust economies in a rugged, mountainous, coastal country located just south of the Equator. Peru’s love affair with seviche is believed to predate Spanish conquistadors, who brought not only disease and mayhem to the Inca Empire in the 16th century, but also the limes that Peruvians would use to “cook” their raw fish. Apparently the lime’s high acid content proved a better partner for raw fish than the native sour oranges and tumbo fruits favored in pre-Hispanic times.

All of that is, though, ancient history as Eddy Ancasi and Javier Angeles-Beron gather at the subterranean bar inside Las Canteras, Ancasi’s Peruvian restaurant in Adams Morgan. Both men are chefs and natives of Peru; Ancasi was born in Arequipa, the country’s second-largest city, while Angeles-Beron hails from Lima, the nation’s capital and largest metropolis with a population of more than 7.5 million.

The chefs share similar views on what constitutes a traditional Peruvian seviche — as opposed to one found in Ecuador, which has its own history and approach to the dish — and the first thing they agree upon is the amount of time the fish should spend in the citrus marinade. If you review some English-language cookbooks dedicated to Peruvian cuisine, they will regularly tell you to marinate the fish for an hour, sometimes far longer. These kinds of directions generate disapproving looks from Peruvians.

If you marinate the fish longer than 15 minutes, says Ancasi, it is “going to become very hard, chewy, almost like rubber. You don’t want that.”

Nor do you want to freeze the fish before slicing it or let the fish reach room temperature before serving it. What you want is fresh, raw, cold seafood — preferably a firm whitefish such as flounder, halibut or even the much-maligned tilapia — cut into rough, bite-size chunks. These chunks should, ideally, sit in their citrus bath for 10 or 15 seconds only, says Angeles-Beron, a catering chef for Bon Appetit Management and former executive chef for Latin Concepts, the Washington group behind such restaurant-lounges as Chi-Cha and Gua-Rapo.

“You cook the outside just to get the color changed by the citrus,” Angeles-Beron says. Peruvian seviche, he adds, is “the art of eating raw fish that, with the right texture, doesn’t make you think you’re eating raw food.”

If such a philosophy toward seafood reminds you of sashimi/sushi, you’re not off base. Japanese immigrants began arriving in Peru in the late 19th century, and their culinary techniques (thinly sliced fish) and ingredients (yuzu citrus, soy sauce) eventually crept into modern interpretations of Peruvian seviches. Both the Japanese and Peruvian approaches to seafood value the texture and freshness of the fish (a lot of printer’s ink has been spilled gushing about the market-fresh fish at Peruvian sevicherias, which tend to close once the day’s catch has been exhausted). Both sushi and seviche probably grew out of early fish preservation techniques as well.

But the main difference between the two can be found in the first bite of each: Sushi masters want you to value the flavor of their high-grade fish. Peruvian chefs, by contrast, may incorporate “okay-to-great fish” in their seviches, says Angeles-Beron, but the seafood is not the sole focus. The combination of flavors is. “If the flavor is not right,” says Angeles-Beron, “it’s not good.”

The three principal elements of seviche are acid, heat and temperature. The acid comes courtesy of the limes, of course, although Peruvians favor tart Key limes instead of the Persian variety commonly found in the States. The heat is supposed to be supplied by either aji limo (a Peruvian’s first choice) or aji amarillo peppers. Because the former is almost impossible to find fresh in America and the latter’s supply can be spotty, chefs often fall back on habaneros or jalapenos. The switcheroo comes at a cost, however.

Like Arizona’s weather, says Angeles-Beron, aji limo peppers have a dry heat, which doesn’t linger on the tongue like the bite of a jalapeno or habanero does. When you stop eating the aji limo, he says, the heat stops. Each bite of seviche, then, is a fresh experience, not one built on the heat of the previous forkful.

Temperature is the final element, and perhaps the trickiest for novices to master. Sure, you could follow the Ecuadoran model and marinate your fish for hours in the refrigerator, achieving the desired chill without a sweat, but that wouldn’t be the Peruvian way. Careful prep, as usual, is key. You can press the lime juice several hours in advance before it starts losing acidity, so once you slice your fish (and any other marinade ingredients), you can add them immediately to the liquid in the nonreactive bowl and start stirring with a nonreactive spoon for the desired time, whether 15 seconds or 15 minutes. To keep the fish cool during this curing period, and to lower acidity, Peruvian chefs typically add a cube or two of ice, working to keepthe temperature of the fish under 40 degrees.

Seviche garnishes can be a sore subject in Peru, particularly among traditionalists who draw a line between the original coastal seviches and those bastardized with ingredients from the Andes, such as sweet potatoes (often boiled with spices and served on the side) and those steroidal ears of white corn (also boiled and served on the side). But at least two garnishes are considered mandatory: cilantro and red onion. The latter should always be served as long, arcing slivers placed atop the seviche, not diced and sprinkled around the fish. Why?

“There’s no explanation for it,” says Angeles-Beron. It’s just Peruvian tradition, much like the slice of tomato on an American hamburger. You would never dice a tomato and sprinkle it on your burger, he suggests.

Once they have mastered the essentials of seviche, chefs, Peruvian and otherwise, often feel free to take the dish in wildly unexpected directions. The “Nikkei” cuisine movement in Peru, influenced by those Japanese immigrants, has added its own East Asian twists on the dish. But seviches now incorporate ingredients as diverse as watermelon, mushrooms, beef tenderloin, spinach pesto and duck, each one stretching and perhaps twisting the definition of “seviche” beyond recognition. (Incidentally, the Royal Spanish Academy dictionary defines seviche as “raw fish or seafood diced and prepared in a marinade of lime or sour orange juice.”)

But no matter how contorted seviche becomes, one practice remains immutable, at least in Peru. It’s the reason seviche comes with both a fork and spoon. After the seafood or main ingredient is gone, and all that’s left is the lime juice infused with natural juices and herbal flavors, locals take their spoon and attack that leche de tigre, or “tiger’s milk.”

“Peruvians would never leave one drop,” Ancasi says.

The juice is supposed to cure hangovers or act as an aphrodisiac, claims I have no way of validating. But I do know this: Acidic tiger’s milk, when paired with cool, fresh seafood, makes the summer a lot more bearable.

RECIPES:

Sardine Seviche

Mushroom Seviche

Las Canteras Seviche

Duck Seviche

More seviche recipes.