Everything home cooks need to know about salt

People often ask me, "Why does the food in restaurants taste better than what I cook at home?" I have a simple answer: salt.

Restaurants deploy salt in ways that home cooks seldom do. Any pot of boiling water destined to cook pasta, potatoes or vegetables is generously salted. Salads are always tossed with salt. (As well they should be: the word "salad" comes from the Latin salata, salted. See also salami, sausage and soused.) Steaks and chops are well-salted before being grilled, and finished dishes are tasted for salt before they are served.

But shouldn't we be reducing the salt in our diets? The question has a complicated answer (see story below), but bear in mind that, according to the Food and Drug Administration, about 75 percent of our total salt intake comes from the salt found in processed foods and in meals consumed outside the home.

A little salt history

Archaeologists have identified saltworks in China that date back to 6,000 BC, according to Mark Kurlansky's definitive "Salt: A World History" (Penguin, $16). By 2,000 BC, the Egyptians were curing meats with salt. Two millennia later, Roman soldiers were paid a salarium (the origin of our word "salary"), which historians believe signified that their compensation was paid in salt, or that they got an additional salt allowance.

"For most of human existence," writes Mark Bitterman in "Salted: A Manifesto on the World's Most Essential Mineral" (Ten Speed, $40), "salt was, literally, a treasure, and everyone everywhere who could make it would," resulting in unique salts, each of which bore a mineral and crystalline imprint of the elemental and human forces that wrought it."

It's only in the last 150 years that salt production has become mechanized. Just as the diversified family farm has given way to industrial mono-agriculture, so "big salt" has obliterated most of the small-scale saltworks that used to . . . pepper the inhabited world.

Cooking with salt

I beg you: salt your pasta-cooking water with at least 1 tablespoon a gallon. You will only be consuming a fraction of it, but the pasta will absorb the salted water as it cooks, rendering it infinitely more tasty. No amount of salt added later can compensate for pasta cooked in saltless water.

Vegetables boiled in salted water not only taste better, they retain their bright color. Salt sprinkled on meats before roasting or grilling helps form a nice crust. And even if a recipe doesn't call for it, always add a big pinch of salt to anything sweet. It will make the flavors deeper and more balanced.

Many cooks prefer kosher salt to table salt. With its larger, flakier grains, it is easier to pinch up, and since an equal measure of kosher salt is less dense (i.e. less salty) than table salt, it can be used with less chance of oversalting. (Cook's Illustrated magazine, in its May 2005 issue, worked out the volume equivalents for the two leading brands of kosher salt: For one tablespoon of regular table salt, use 1 1/2 tablespoons Morton kosher salt or 2 tablespoons Diamond Crystal kosher salt.)

Types of salt

Both table salt and kosher salt are obtained via "solution mining," in which underground salt mines (as in "Back to the salt mines!") are flooded, the water dissolves the salt, and the resultant brine is pumped out and evaporated. Often, potassium iodide or potassium iodate is added to table salt. Iodized salt was introduced by Morton Salt in the 1920s when it was discovered that a diet low in iodine led to goiter, an enlargement of the thyroid.

Salt connoisseurs eschew solution-mined salt, preferring rock salts (among them Himalayan pink salts from Pakistan and Jurassic salt from Utah) that have literally been hewed from rock, and sea salts such as Maldon sea salt from England, Trapani sea salt from Sicily and fleur de sel. Despite its French name (which means "flower of salt"), fleur de sel is not a regional salt, but a term that describes a production method used the world over: As seawater naturally evaporates, fleur de sel is the crust that forms on the water's surface. "Sel gris" (gray salt) is produced when evaporation is complete.

The allure of artisanal salts is manifold. They add not only saltiness to food, but the flavor of whatever trace minerals they contain. According to Bitterman, "on their own, they actually taste like food - not like a chemical - and they make everything taste warmer and richer and fuller."

Bitterman sees the growing popularity of local, traditionally produced salt as very much in line with other culinary trends. "People are becoming more mindful of the foods they eat - organic vegetables, grass-fed beef. Salt is just one more ingredient that requires being thought of the same way.

You don't salt your pasta water with artisanal salts (use a naturally evaporated sea salt such as the French brand La Baleine ("the whale"), or a relatively inexpensive sel gris). Instead, use them to "finish" dishes: sprinkle a little fleur de sel on a steak; its residual moisture will keep it from melting. Finish sauteed vegetables with crunchy, pungent Maldon sea salt.

Where to buy salt

Most supermarkets carry La Baleine, which has been produced in Camargue, France, since 1856. Specialty markets such as Whole Foods and Fairway stock a wider range of artisanal salts. Penzeys Spice (visit the store in South Huntington or go to penzeys.com) recently started selling several well-priced salts; saltworks.us has a large selection, as does atthemeadow.com.

The health debate

It's the sodium in sodium chloride that takes the heat when salt gets slammed for contributing to high blood pressure, stroke and heart disease. Humans need sodium to live, but most people consume more than what the body requires to function - about 500 mg a day, according to Sharon Akabas, director of the master's program at Columbia's Institute of Human Nutrition. The FDA estimates that the average American consumes about 3,400 mg a day, and the Department of Agriculture's current Dietary Guidelines suggest that 2,300 mg be the limit for the general population.

Limiting sodium

How much is 2,300 mg of sodium? About one teaspoon of table salt. But consider that three-quarters of the salt we consume doesn't come from salt added at the stove or table, but from salt present in processed foods and restaurant meals. (A half cup of Newman's Own marinara sauce contains 510 mg sodium; the same amount of canned, peeled tomatoes contains 220 mg.)

With figures like these, even FDA spokeswoman Siobhan DeLancey conceded that "it's challenging to consume a diet with processed food and restaurant foods and stay below 2,300 mg of sodium."

The task may get a bit easier, however. The New York City Health Department has spearheaded a national campaign whereby restaurants and food manufacturers voluntarily reduce the amount of salt in their products, with the goal of reducing intake by 20 percent over five years. Boar's Head, Goya, Heinz, Kraft, Starbucks, Subway and Au Bon Pain are among the companies that have committed to this effort.

But is salt bad for you?

There is agreement among nutritionists and scientists that sodium levels are linked to hypertension (high blood pressure). "About one-third of Americans have high blood pressure," Akabas said, "and close to two-thirds have 'salt sensitivity,' that is, that a change in their dietary intake of salt may result in a change in blood pressure."

Here's where things get complicated. Dr. Michael Alderman, professor of epidemiology and population health and of medicine at the Albert Einstein College of Medicine, has emerged as a leading critic of the "salt is bad" camp. First, he says, even drastic reductions in sodium intake have modest benefits - on average, three or four points of decrease in blood pressure when sodium intake is slashed in half from 3,600 mg.

And, according to Alderman, lower sodium intake leads, among other things, to an increase in insulin resistance (a risk factor for diabetes), as well as sympathetic nerve activity and aldosterone production, both of which increase the risk of heart attack. In other words, reducing sodium may have a salutary effect on hypertension, "but that doesn't mean that it makes you live longer or better. The net effect on your health of lowering your sodium is a combination of all the factors."

Alderman also is wary of nutritional guidelines. "The problem is unintended consequences. In 1980, the national dietary guidelines called for a low-fat diet. What happened? It turned out that people ate more calories. The guidelines were reversed in 2000."

Finally, he pointed out that American sodium intake has remained constant at around 3,600 mg since 1957. In that same time "stroke and heart-attack deaths have dropped by more than half."

Recipes

PRESERVED LEMONS

Preserved lemons are a common ingredient in North African and Middle Eastern cooking. In his book "Salted: A Manifesto on the World's Most Essential Mineral" (Ten Speed, $40), from which this recipe was reproduced, Mark Bitterman writes that "the citrus and salt goad each other on in a warrior's dance ...and in your mind ring the bells of camels and the beat of rawhide tambourines. Simmer chicken in diced preserved lemon, olives and fresh coriander for a superb tagine. Make a compound butter of minced preserved lemon, ancho or española peppers and cilantro to serve over pan-fried fish. Chop preserved lemon with parsley, dill, shallots and olive oil for a relish to top anything from rack of lamb to a goat-cheese tart."

8 large lemons, scrubbed clean

About 3 cups sel gris (gray salt)

8 juniper berries (optional)

Fresh lemon juice, as needed

1. Cut the tips off the ends of the lemons. Cut each lemon into quarters lengthwise, leaving them attached at one end. Pack the lemons with as much salt as they will hold. Insert one juniper berry into each lemon.

2. Put the lemons in a sterilized wide-mouth quart-size jar, packing them in as tightly as possible. As you push the lemons into the jar, some juice will be squeezed from them. When the jar is full, the juice should cover the lemons; if it doesn't, add some fresh lemon juice.

3. Seal the jar and set aside, unrefrigerated, for 3 to 4 weeks, until the lemon rinds become soft, shaking the jar every day to keep the salt well distributed. The lemons should be covered with juice at all times; add more as needed. Rinse the lemons before using. Makes about 1 quart.

CLASSIC DRY-FRIED PEPPER AND SALT SHRIMP

"The absence of liquid in the stir-fry allows you to experience a concentrated shrimp flavor accented by garlic, ginger, chilies and Sichuan peppercorns," writes Grace Young in her "Stir-Frying to the Sky's Edge" (Simon & Schuster, $35)

2 tablespoons plus 1/2 teaspoon kosher salt

1 pound large shrimp, peeled and deveined

1/4 teaspoon sugar

1/4 teaspoon roasted and ground Sichuan peppercorns (see Note)

2 tablespoons peanut or vegetable oil

1 tablespoon minced garlic

1 tablespoon minced ginger

1 teaspoon minced jalapeño chili, with seeds

1. In a large bowl combine 1 tablespoon of the salt with 1 quart of cold water. Add the shrimp and swish them in the water with your hand for about 30 seconds. Drain. Add 1 more tablespoon salt to the bowl with 1 quart of cold water and repeat. Rinse the shrimp under cold water and set on several sheets of paper towels. With more paper towels, pat the shrimp dry. In a small bowl combine the remaining 1/2 teaspoon salt, sugar and ground Sichuan peppercorns.

2. Heat a 14-inch flat-bottomed wok or 12-inch skillet over high heat until a bead of water vaporizes within 1 to 2 seconds of contact. Swirl in 1 tablespoon of the oil, add the garlic, ginger and chili, then, using a metal spatula, stir-fry 10 seconds or until the aromatics are fragrant. Push the garlic mixture to the sides of the wok, carefully add the shrimp, and spread them evenly in one layer in the wok. Cook undisturbed 1 minute, letting the shrimp begin to sear. Swirl in the remaining 1 tablespoon oil and stir-fry 1 minute or until the shrimp just begin to turn orange. Sprinkle on the salt mixture and stir-fry 1 to 2 minutes or until the shrimp are just cooked. Makes 2 main-course servings with rice or 4 servings as part of a multicourse meal.

Note: To roast Sichuan peppercorns, place them in a small dry skillet over medium heat and cook, stirring constantly, until you begin to smell their fragrance. Remove from skillet immediately so they don't burn.