Manao (Lime)

Manao is the Thai name for the small, thin-skinned, intensely acid green lime, Citrus aurantiifolia, the Key or West Indian lime of the markets. It reached Thailand from the Indo-Malayan region, where the citrus family is native, and it has long been grown in the gardens and orchards of the central plains, whose warm, wet soil suits it. It is carried by every Thai cook as the principal fresh acid of the kitchen, and it belongs to the tradition of the street and the table, where a dish is balanced at the last moment by the person who eats it. David Thompson, in Thai Street Food, shows the lime as an ordinary companion of the street vendor: halved beside noodles, pressed into salads and dipping sauces, and served on the side so that the eater may correct the dish.

The fruit is small, round and thin-skinned, roughly the size of a large walnut to a small hen's egg, green when picked and yellowing as it ripens. The flesh is pale green to yellow, very juicy, with many small seeds, and the juice is sharply acid with a floral, resinous perfume that comes largely from the oils of the skin. It is distinct from the makrut, Citrus hystrix, whose knobbled rind and leaf are used for aroma and whose juice is little used, and from the larger, seedless Persian lime of export trade. In the Thai kitchen the lime is used in several ways: the juice squeezed fresh into salads, soups, dressings and dipping sauces; the halves served at the side of the plate; and, less often, the zest or the whole fruit bruised into a drink or a pickle. The juice is always pressed to order, since it loses its brightness within hours of squeezing.

Lime is eaten with the rich, the salty and the fried: grilled meats and fish, noodle soups, fried rice, and the many salads and dressings in which fish sauce, palm sugar and chilli are balanced against its acid. It is drunk as fresh lime juice sweetened and lengthened with water, and it sits well beside cold beer and iced tea. The structural reason is balance: acid cuts fat, lifts salt and sweetness, and refreshes the palate between mouthfuls, so that a heavy dish stays bright and the chilli's heat is carried rather than dulled. The perfume of the skin oils adds an aromatic note that the bottled or long-held juice does not have.