Kaffir lime is used extensively in Thai cooking. Both the zest and leaves are very useful. The fruit looks like a wrinkled lime, big wrinkles. Thai people believe the juice is excellent hair rinse to prevent hair from falling out. The zest of the lime is a key ingredient in red and green curry pastes.
The juice is used in a few Thai dishes, but the zest is more common.
Recently, Thai growers have developed and started growing a kaffir lime without wrinkles that is easier to pack and ship around the world.
kaffir lime leaves
Bai Magrood ใบมะกรูด
Kaffir lime leaves are thick, dark green and shiny on the top, porous and pale on the back. A leaf has two connecting leaves which I call ‘double leaves’. Tear a leaf to smell the distinct aroma. Fresh kaffir lime leaves keep well in a refrigerator for at least 2 weeks. Dried leaves are also available at markets. Many Asian markets now have fresh leaves.
If the recipe calls for kaffir lime leaves and you can’t find any, skip the leaves. Don't substitute. The fragrance is so distinct that it is irreplaceable.
How to Use Kaffir Lime Leaves
Kaffir lime leaves are too tough to just eat, so they're either kept large and reserved, or sliced thin. Many Thai recipes call for the kaffir lime leaves. If the leaf is used whole, like in curry or in soup, most people do not eat the leaf itself. To prepare, tear the leaf by holding on to the joint between the two leaves and tear the leaf away. When you eat, you just avoid eating the leaf and move it to the side of your plate or bowl.
The only time the leaf is eaten is when it is sliced very thin for recipes like Tod Mun and Panang. To slice or thread the kaffir leaves, roll up the leaves and slice thinly with a very sharp knife. Check out the 2 pictures on the the right, one was taken in 2000 and another in 2012. See how I've improved my slicing skill? It took practice and a better knife.
How to Grow a Kaffir Lime Tree
I have grown a few Kaffir lime trees, either picking them up at the home improvement stores or growing them from seeds. They seem happy in a large pot, like a half wine barrel. In such a pot, they grow to about 3 feet tall. Even with a single 3 foot tall tree, we get more leaves than we can use.
When we lived in a cold climate, we’d bring it inside the house during the winter, then back out in the summer. Now in a warmer climate, my kaffir lime trees stay outside all year round.
Like other citrus, the fruits are ready in fall and winter. I have made homemade curry pastes with the zest. The aroma of the zest freshens up the house every time I make curry pastes.