Bitter melon is eaten in both ripe and unripe forms. I find the unripe form harsher and less complex, although it is also less bitter. As it ripens, the flesh developes a translucence reminiscent of jadeite
, and the matter around the seeds may become orange or even a beautiful deep red color.
My favorite preparation of this vegetable is stir-fried with hard-boiled, salted duck egg (readily available in many East Asian groceries). The two ingredients are strong and set each other off with power.
Dried and sliced, bitter melon is used as a tisane in China and Vietnam. It is bitter, though not as bitter as the melon itself, and it has a mild underlying sweetness that is pleasant. Bitter things are generally considered "cooling" in traditional East Asian medicine, and bitter melon tea is held to be suitable as a warm weather drink. As with most infusions, it is said to be diuretic, and is also considered good for the stomach, the eyesight, and the liver and gallbladder. As in all matters of herbal medicine, I invite you to believe as you choose. I drink it because I like the taste.
The Mandarin name is ku3-gua1 cha2, Vietnamese is tra kho qua (sorry, I don't have the font to make this exact). On one Vietnamese label I have seen recently on the East Coast of the U.S. it is called "Gohyah Tea", and on another "Green Tea" (!) - caveat emptor. Packages brought back from Taiwan street vendors have generally been full of ants.