Galangal / Thai Ginger
Galangal is also know as Thai ginger or Siamese ginger but you can not substitute the commonly used ginger for galangal.
Galangal is commonly found in Thai, Indonesian, and Malaysian cooking. The skin of galangal is pinkish, smoother and paler than ginger and its flesh ranges from white to yellow to pink and is much harder. To prepare it for soup or curry, peel off the skin. Its normally not grated like ginger, but is instead normally finely sliced. It also has a whiter flesh and is much denser than ginger. The flavor of galangal is much stronger and more astringent too; it’s earthy, sharp, and extra citrusy. Galangal has a sharp citrusy, almost piney flavor.
Galangal is recognizable by the long pink stalks and pink tips on the root.
Galangal is the khaa in Tom Khaa. Tom kha kai (or tom kha gai) is a Thai soup with the distinct, very Thai flavor of galangal. Kha means "galangal" in Thai. Also used in Tom Yum and curry pastes.
Note: Images are only for illustrative purposes, actual product and colour may slightly differ.