Galangal (galanga, blue ginger, laos) is a rhizome of plants of the genus Alpinia or Kaempferia in the ginger family Zingiberaceae, with culinary and medicinal uses originated from Indonesia. (Lao: ຂ່າ "kha"; Thai: ข่า "kha"; Malay: lengkuas (Alpinia galanga); traditional Mandarin: 南薑 or 高良薑; simplified Mandarin: 南姜 or 高良姜; Cantonese: lam keong, 藍薑; Vietnamese: riềng).
It is used in various Asian cuisines (for example in Thai and Lao tom yum and tom kha gai soups, Vietnamese Huế cuisine (tre) and throughout Indonesian cuisine, for example, in soto). Though it is related to and resembles ginger, there is little similarity in taste.
In its raw form, galangal has a citrusy, piney, earthy aroma, with hints of cedar and soap (saponins) in the flavor; its flavor is a complement to its relative ginger, but galangal has little of the peppery heat that raw ginger has. It is available as a whole rhizome, cut or powdered. The whole fresh rhizome is very hard, and slicing it requires a sharp knife. A mixture of galangal and lime juice is used as a tonic in parts of Southeast Asia. In the Indonesian language, greater galangal is called lengkuas or laos and lesser galangal is called kencur. It is also known as galanggal, and somewhat confusingly galingale, which is also the name for several plants of the unrelated Cyperus genus of sedges (also with aromatic rhizomes). In Thai language, greater galangal is called "ข่า" (kha) or "ข่าใหญ่" (kha yai), while lesser galangal is called "ข่าตาแดง" (kha ta daeng). In Vietnamese, greater galângl is called riềng nếp and lesser galangal is called riềng thuốc.
The word galangal, or its variant galanga, in common usage can refer to four plant species all in the Zingiberaceae (ginger family):
Alpinia galanga is also known as chewing John, little John chew and galanga root. It is used in African-American folk medicine and hoodoo folk magic.
Polish vodka Zoladkowa Gorzka is flavoured with galanga.
The rhizome of Alpinia galanga has shown antimalarial activity in mice.[1]