Kaffir lime is used extensively in Thai cooking. Both the zest and leaves are very useful. The fruit looks like wrinkled lime, big wrinkles. Thai people believed the juice is excellent hair rinse to prevent hair from falling out. The zest of the lime is an ingredient in red curry paste.

The juice is rarely used in Thai cooking, but the zest is common.

Recently, Thai growers have developed and started growing a kaffir lime without wrinkles that is easier to pack and ship around the world.

The leaf look like any citrus leaf, but it has two connecting leaves. I often call it the double leaf. Many recipes calls for its leaves. If the leaf is used whole, in soup, most people do not eat the leaf itself. The only time the leaf is eaten is when it sliced very thin for recipes like Tod Mun.