General Information
Kaffir lime leaves are small to medium in size and oblong in shape, averaging 3-5 centimeters in diameter and 8-12 centimeters in length. The top of the thick leaves is glossy and deep green, while the underside of the leaves is porous and a pale, matte green. Kaffir lime leaves grow in pairs and grow in a double leaf formation, which means two leaves grow on either side of the stem and appear to mirror each other. There is a prominent central midrib or vein and the tips of the leaves can be slightly rounded or very pointed. Kaffir lime leaves have a strong citrus taste and aroma that is said to be a blend of mandarin orange, lemon, and lime.
A fragrant and necessary ingredient in Thai, Laotian and some Vietnamese and Indian cooking, the kaffir lime tree has other common names, including kieffer lime, Thai makrut and limau puru. The leaves are known as bai magrood and are harvested from the evergreen tree native to Southeast Asia. The English name kaffir may be based on colonial slang and come chefs prefer to call this ingredient by it’s Thai name, makrut.
Characterized by the unique figure-eight shape of it’s double leaf, this ingredient is also identified by it’s distinct and explosive bright, floral and citrusy aroma. The upper side of the leaf is dark green and glossy and the underside is a lighter green with no sheen. The darker the leaf, generally the more mature and aromatic the ingredient.
The leaves have a strong fragrance and flavor for which there is no ready substitute. If the leaves are to be used in a culinary application, it is best to break apart the pairs and remove the thick stem running centrally down the petiole. Stack several leaves and shred finely (chiffonade) to impart the most flavor to the dish. The leaves keep well in a plastic bag, refrigerated. They freeze well and can be kept for up to a year frozen, without losing any texture or aroma. Dried leaves are available from a variety of sources but prove to be a less than mediocre substitute for the fresh variety.
History
The kaffir lime tree is native to tropical Southeast Asia and was spread to neighboring regions via exporters and trade routes. Today Kaffir lime leaves are available in fresh markets and frozen in specialty grocers in Asia, Southeast Asia, Africa, the United States.
