kah in Thai and known as galangal, Siamese ginger, Thai ginger, and laos root
Galanga Root (kam) Galanga, called kah in Thai and known variously as "galangal" and "laos root," is an immensely pungent and fiery rhizome related to the common ginger but with a personality distinctly its own. Its abundant usage in Thai cooking, almost to the exclusion of ginger, has earned it the title of Siamese or Thai ginger. In short, it is to Thai cooking what common ginger is to Chinese cooking.
There are two different varieties, one known as "greater galanga" and the other, "lesser galanga." The first, which is larger in size, lighter in color and subtler in aroma, is the kind most used in Thai cooking. The fresh root is fleshy, knobby and very firm, to the point of being woody when it fully matures. When very fresh, its ivory color, with hardly any separation between skin and flesh, and its young pink shoots are reminiscent of the appearance of young ginger. But unlike its better-known cousin, it is much denser and harder with ringlike markings spaced almost evenly apart, a glossy outer sheen, a unique mustard-like flavor and a much sharper bite. You will not need much of it to flavor a dish.
Cultivated in hotter areas of California and Florida, galanga is also imported fresh from countries south of the border and flown in from South Pacific islands. These foreign-grown rhizomes, however, differ somewhat in flavor from the roots grown in the soil of tropical Thailand, which seem to have a wider range of attributes. Imported frozen Thai galanga is readily available in Southeast Asian markets. Although some of its fresh punch is compromised by freezing, it still carries important gradations of flavors lacking in foreign-grown roots, making it my preferred choice for curry pastes with robust characters. Frozen Thai galanga is usually small and has a light reddish brown skin and usually costs much less than the fresh cream-colored roots.
Galanga has many medicinal properties similar to ginger. It is a digestive stimulant and also helps to settle stomach upsets, ease nausea and curb flatulence. Traditional herbal doctors recommend a tonic made of minced and pounded old galanga root, mixed with tamarind water and salt, for women who have just given birth, as a blood purifier and as an aid in the removal of gas build-up in the intestines. At the same time, its mild, natural laxative effect keeps the bowels regular. Galanga's heat makes it a good agent in reducing cramping and numbness, in healing bruises and swelling, in treating respiratory ailments and skin diseases and in removing toxins from the body.
In addition, kah is sometimes classified among the category of herbs we call wahn, which are reputed to have magical powers. This belief coincides with an account about its use in medieval Europe among certain medicine people, who wore the dried root as a protection against evil influences and as an enhancer of virility. Known as "galingale" during that period, it was widely used as an aphrodisiac as well as a spice. Somehow, it disappeared from European culinary and medical scenes, and some historians have surmised that it fell out of vogue, along with other spices, as milder foods became the order of the day in the eighteenth century. Today, as Thai cuisine grows in popularity on that continent, perhaps galingale will regain its favored position.
Like other members of the ginger family used in Thai cooking, galanga's pungent spiciness freshens the taste of seafood, making it a valued herb in seafood salads and soups. For salads, slice the root as thinly as possible, then stack several slices at a time and cut into very fine slivers; for soups, thin slices are simmered to flavor the broth. Galanga is also an essential ingredient in most Thai curries and is chopped and pounded to a paste with other paste ingredients. When buying galanga, select a young rhizome that is as light in color as possible with pinkish shoots and few or no brown spots. Avoid large, fat roots, as these can be very hard and woody, making it almost impossible to cut. Sometimes a piece you get will be tender at the tips and woody further down; save the tender end for salads and use the more fibrous section for seafood soups.