Specification :

Karkade (pronounced "KAR-kah-day") is a sweet tea. Karkade is the Arabic word for the roselle plant (Hibiscus sabdariffa).
Karkade is a tart, bright-red hibiscus beverage that can be served hot or chilled with ice (when cold, it is often commonly referred to as Einab). It is very popular in some parts of the Middle East (especially North Africa). This drink is said to have been consumed in ancient Egypt and was reputedly a preferred drink of pharaohs. In Egypt and Sudan, wedding celebrations are traditionally toasted with a glass of hibiscus tea. On a typical street in downtown Cairo, one can find many vendors and open-air cafés selling the drink to both the local crowd and curious tourists.
In Africa, especially the Sahel, roselle is commonly used to make a sugary herbal tea that is commonly sold on the street. The dried flowers can be found in every market. In the Caribbean the drink, called sorrel, is made from the fresh fruit, and it is considered an integral part of Christmas celebrations. The Caribbean Development Company, a Trinidad and Tobago brewery, produces a Shandy Sorrel in which the tea is combined with beer.
In Thailand, roselle is drunk as a tea, believed to also reduce cholesterol. It can also be made into a delicious wine - especially if combined with Chinese tea leaves—in the ratio of 1:4 by weight (1/4 Chinese tea). It is also drunk cold and sugared.
Variations on the drink are also popular in West Africa. In Senegal, jus de bissap is known as the "national drink of Senegal". Similar beverages include wanjo in The Gambia and zobo or tsobo in northern Nigeria.
In Egypt, karkade is used as a means to lower blood pressure if consumed in high amounts.