Grass jelly is certainly not much to look at, jiggling on a plate with its shiny black or dark green appearance. Admirers of the Asian jelly-like dessert say diners should try to overlook its appearance and not pass up a chance to give it try if they find grass jelly on the menu. A plant-based food, it is pleasant-tasting to many, and some proponents also tout its purported benefits for better health. Others who have tasted it report that it is slightly bitter. Grass jelly, also called leaf jelly, can be found in iced desserts, drinks and snack foods.
Manufacturers make green jelly from a plant called mesona chinensis, which belongs to the mint family of herbs. Although the jelly is popular in Taiwanese dishes, the country’s climate is not conducive to growing the herb and much of the product must be imported from other Southeast Asian countries. The manufacturing process includes several hours of boiling the dried herb down into a gelatinous and gummy substance. During this part of the process it smells very medicinal. After the hours of boiling, the mixture is strained and then kneaded with a bit of flour. After hours of work, the substance is finally ready to be formed by cooling in trays into the cubes that are known as grass jelly.
The consistency of green jelly is similar to that of aiyu jelly, which is manufactured from figs. Cooks use green jelly in a wide variety of recipes, including pairing it with fruit and ice for dessert, and even as a beverage, albeit a thick one that relies on melting to achieve the desired consistency in certain dishes. Chefs at some Taiwanese restaurants enjoy mixing grass jelly with traditional flavorings such as chocolate or strawberry. Diners who have come to enjoy grass jelly say it is a cooling dish.
Manufacturers claim the green jelly is beneficial for a number of health problems, including the common cold, infections and high blood pressure, although there are no scientific studies to back up this claim. Some women in Vietnam turn to grass jelly drinks to improve their fertility. It is a popular ingredient in many Asian cultures, and the variety of names bestowed on green jelly reflects its widespread use. In Taiwan it is known as chao kuay, while in Singapore it is referred to as chin chow. The Vietnamese named it suong sam, and in Malaysia it is cincau.
(Source : http://www.wisegeek.com)