From our friend C.H. -
Butterfly pea flower – ดอกอัญชัน – is widely used by Thais to color food. It also has great medicinal value. Tasted ok too, but I think I prefer my cut flowers in a vase.
Here is a story about the flower I found: What is that flower behind your ear? นั้นดอกอะไรอยู่หลังใบหูของคุณ. In a Thai village, the answer might be that is is a jasmine, hibiscus or butterfly pea flower. You often see women or men in Thai villages wearing flowers behind their ears on special occasions..a blue butterfly pea flower.
In addition to wearing a blue butterfly pea flower - ดอกอัญชัน (dok anchan) or Clitoria ternatea – behind your ear while working in a garden, it has properties as a Thai culinary flower. Butterfly pea is an annual vine that is native to the land in SE Asia near the equator. Thai’s love doc anchan for its beautiful, unique looks as well as for its culinary uses as a food coloring and edible flower. Some use dok anchan in their Thai cooking, shredding it into a fine ribbon and adding it to rice salad, making a tea or adding blue color extract to steamed jasmine rice. Many hotels in Thailand greet guests with a welcome drink made from dok anchan. But above and beyond all these uses, ancestors recognize it for its medicinal benefits, which include its anti-depression, anti-inflammatory and anti-cancer properties. The blue concentrate added to hair products also promotes healthy hair growth.
The vines can produce many flowers a day. The pigment in the flowers come from anthocyanins, and has long been widely used in Thai and Malaysian cuisines for blue or purple food coloring for butterfly pea sticky rice. In Thailand, any foods prepared with shades of blue, purple or pink come from dok anchan. In addition, SE Asia uses the flowers in traditional Ayurvedic medicine, a system of traditional medicine native to the Indian subcontinent and a form of alternative medicine for the treatment of various ailments.
In the U.S. you can mail-order homegrown organic air-dried butterfly pea flowers from Esty.com and Alibab.com.
Step by Step Instructions for making blue and purple Butterfly Pea color extracts –
1. Steep 12 dried or fresh butterfly flowers in 1 cup of boiling water
2. 15 minutes later or when no color is left in the petal, strain the liquid and discard the flowers. You will get deep, blue water.
3. Add a few drops of lime juice. This will change ph level and you will get purple water.