At the risk of sounding older than I really am, I remember the days before lime became chic, when fresh limes were hard to find and most cooks had to make do with the sour juice in a fruit-shaped squeeze bottle.
That was before la nouvelle cuisine made lime the premier citrus fruit of the '80s. It was also before Perrier, with its inevitable wedge of lime, became the quaff of a nation. Few Northerners had ever tasted a Key lime. As for the perfumed kaffir lime from Thailand, it might as well have grown on the moon.
How we cooked without fresh lime juice boggles my imagination. Without it, there would be no daiquiris, no ceviche, no Key lime pie. Everything from salad dress-ings to marinades and sorbets would taste bland. In this age of reduced salt and low-fat cooking, lime is a miracle worker. It adds flavor and piquancy (not to mention loads of vitamin C and potassium), without calories or cholesterol. A lemon is merely sour, while a lime has both tartness and an exquisite taste.
The association of lime with warm-weather cooking is no accident. Limes are believed to have originated in India or Malaysia. The fruit requires a semi-tropical climate for growing. (Most of the limes consumed in the U.S. come from southern Florida and Mexico.) Limes were first grown on a large scale in southern Iraq and Persia. (Our word lime comes from the Arabic "limah.") The Moors introduced lime trees to Spain and southern Italy. The fruit isn't mentioned in English until 1638. Columbus liked limes enough to bring them to the New World in 1492.
To most people, lime means Persian lime, the plump, dark-skinned, seedless fruit we cut into wedges for garnishing cocktails. (The tree is propagated by cuttings.) Persian limes are appropriately named, as the fruit was first grown commercially in what today is southern Iraq. Today, Persian limes are a multimillion dollar industry in southern Florida, which supplies half the limes used in the United States.
The Key lime is a small (10 to 12 to a pound), yellowish-green fruit with a bracingly acerbic juice. Also known as Mexican lime or West Indian lime, the Key lime was extensively cultivated in the Florida Keys in the 19th and early 20th century. Key lime is the preferred lime throughout the Caribbean and Central and South America.
Key lime isn't for everybody, however. The trees are full of thorns, and the fruits are full of seeds. The juice has a mild acrid aftertaste that can be off-putting, although it's perfect for balancing the cloy of the sweetened condensed milk in Key lime pie. Key limes are acidic, but because they're picked at a riper stage than Persian limes, they also have a touch of sweetness. The tiny yellow fruit is available irregularly year round; peak season is winter. Most of the Key limes sold in the United States come from Haiti.
The world's most unusual lime is without a doubt Citrus hystrix, the kaffir lime, a pear-shaped fruit with a wrinkled warty rind. Popular in Southeast Asia, kaffir lime is prized for the perfumed oil in its skin and its leaves. (The latter taste like lime-scented bay leaves.) Grated kaffir lime rind is an essential ingredient in Thai curry paste, while the shredded leaves turn up in Thai hot and sour soup. You can also use the juice, but the fruit contains relatively little in proportion to its seeds. Thai peasants believe that washing your hair with kaffir lime juice will ward off evil spirits. Look for this unusual lime in Asian produce markets. The leaves are sold fresh, frozen and dried.
This brings us to the tangerine lime, which is sometimes sold at Hispanic markets. This large, round, green fruit with orange pulp and sour orange juice is a variety of the bitter orange.
The lime offers the cook two dynamic flavors: the sour juice and the aromatic oils in the rind. These oils are concentrated in the "zest," the dark outer rind. Remove it with a zester (a tool with a perforated flat blade), or a vegetable peeler, or a grater. Avoid the white pith, which is bitter.
To juice a lime, roll it hard on a work surface to rupture the juice sacs inside. Limes are drier than lemons, so you'll need to press hard. Depending on the size, a Persian lime contains two to four tablespoons juice. To make one cup of Key lime juice you'll need 10 to 14 Key limes.
The following dish could be thought of as French sashimi. Although uncooked, the fish isn't really raw: it is "cooked" by the acidity in the lime juice. This recipe comes from the restaurant Le Flamboyant in St. Barthelemy in the French West Indies. There, it is often prepared with grouper instead of salmon.
12 ounces fresh salmon
1 clove garlic
1/4 cup finely chopped parsley
2 tablespoons finely chopped chives
3 tablespoons fresh lime juice, plus 8 lime wedges for garnish
3 tablespoons extra virgin olive oil
salt and fresh black pepper
Cut the salmon on the diagonal into paper-thin slices. Mince the garlic, shallots, parsley and chives.