The lime leaves referred to here have no relationship to the linden or lime tree of Europe {Tilia curopaca). There are other varieties of citrus lime trees Mexican lime, Tahitian lime, and West Indian lime which are similar to kaffir lime, but these are different again in flavor. The kaffir lime is a typical evergreen citrus tree with dark green, smooth leaves that are long and flat, and are distinguished by their shape, having a marked indentation on each side of the leaf. The aromatic foliage is high in volatile oils, which give the leaves their unique flavor. The branches have long, sharp thorns, so be wary! In summer the white, fragrant flowers come into bloom, later followed by small green limes that are only moderately juicy.
History and mythology
All citrus trees are native to Southeast Asia, and it seems likely that they were first introduced to Europe in the middle ages by Moorish and Turkish invaders. In northern Europe, special heated glasshouses known as “orangeries” were built so that citrus trees could be protected from the colder climate.
Cultivation
As kaffir limes are grafted trees, buy them ready to plant from a nursery. Choose light, deep, well- drained soil in a sunny, frost-free position. Kaffir limes are tropical trees, and it is not advised to grow them in cold climates except under conservatory conditions. All citrus are surface rooting trees, and need mulching to prevent quick evaporation of moisture from the soil, especially in dry weather. Keep weed-free and give the tree a good soaking in dry weather, rather than watering lightly. As citrus trees are gross feeders, an annual application of some good fertilizer is necessary in the spring. Be careful to cultivate near the surface so as not to injure or cut the fine, shallow roots. By fertilizing and cultivating regularly as the tree grows, the roots are encouraged downwards and are in a better condition to resist dry, hot weather. Prune away dead wood, being careful of the long thorns. Nurseries will advise on the best methods for guarding against scale and other citrus insect pests.
Harvesting and processing
If possible, harvest your own fresh lime leaves as needed. Apart from the “wet markets” of Asia, fresh lime leaves are not always available for purchase, but are becoming more frequently seen in greengrocer shops. Fresh lime leaves can be hung in bunches like bay leaves, and used in varying degrees of dryness.
Various uses
Culinary
Lime leaves are best used straight from the tree for maximum fresh¬ ness and flavor. They are used extensively in Asian cooking, in sambals, with steamed fish, and the beef rendang (curry) of Indonesia. They add a nuance of freshness to chicken soup or fish dishes. In India, Sri Lanka, China and Southeast Asia, the leaves, and the juice and rind from the fruit, are all used in cooking. If kaffir lime leaves are not available, lemon leaves, or leaves from the West Indian and Tahitian lime may be substituted.