Native to mainland southeast Asia, this species of green, flowering plant is used primarily and extensively in the food of Isan (northeastern Thailand) cuisine and Lao cuisine as well. A climbing plant with deep green leaves and yellowish flowers, it thrives in the hot, humid parts of Thailand and Laos and can tolerate only a very mild frost without dying.
Yanang leaves are used in the preparation of keng noh mai som, a rather sour soup which often includes bai-toey leaves, bamboo shoots, chilli peppers, salt, acacia, straw mushrooms, oyster mushrooms or other ingredients. Up until 20 years ago or so, before the desertification of the Isan region had deteriorated to the extent visible today, these ingredients were commonly and cheaply available in almost every village market in the Isan region.
Normally, the Yanang leaves are not used in uncut natural form, rather they’re juiced or pulped, so that an extract is produced. This extract or pulp is included primarily to thicken the soup instead of for its flavouring ability. The flavor, however, is subtle and still comes through. Some prefer to prepare this juice from scratch, some from fresh Yanang leaves and others are happy to start their keng noh mai with canned, commercially available extract.
It should be noted that keng noh mai is quite different from keng noh mai som, involving substitution of pickled vegetables for the souring agent, and often leaving out the Yanang leaves or Yanang extract. Normally closely associated with bamboo shoots and yod-mapao, there isn’t much more than this for Yanang leaves. If the hunger for Isan food in the form of keng noh mai turns up an absolute lack of bamboo shoots, fresh or otherwise, then coconut meat (yod-mapao) is the make-do substitute.
Product of Thailand