Yak butter tea is a combination of water, black tea, yak butter, and salt served in Tibet, Nepal, Bhutan, and other areas where there is a strong Tibetan Buddhist influence and Yaks are kept. Yak butter tea may be served when a friend or guest is present, as part of a meal, or, frequently, as part of a festival. At a festival or other religious occasion, it may be served with beaten, fried maize, which is meant to be placed in the tea and eaten after finishing the tea.
Yak butter tea is made by first churning Yak milk until it becomes somewhat thick. Black tea is then brewed and poured into the churn with the butter. This mixture is churned until the butter and the tea mix thouroughly. A small amount of salt is added prior to serving, for taste. Yak butter tea is consumed in the same manner as regular tea, except that sugar or milk are never added.
The flavor of this tea is mostly that of Yak butter - somewhat like goat cheese, but not so strong, and a bit more gamey - with distinct taste of salt, and just a hint of tea. The Yak butter and salt overpower the taste of the tea, though it is certainly present. The tea tastes like black tea with really heavy cream and a hint of salt - which, essentially, it is.
Some say that the tea tastes disgusting - I disagree. On a cold day, the combination of fat and caffeine is just what is needed to provide energy and motivation. At the high altitude that Yaks are raised at - almost always at least 8,000 feet above sea level - this tea tastes wonderful - there is something about the combination of the thin air and the cold wind with the Yak and the tea that just work well in the situation. Perhaps it imparts something of the Yak into the drinker. More likely, it is has just been designed so well, to work perfectly in the high Himalaya, by the herders and people who have been here for centuries.