Yak byproducts may not be the first thing that comes to mind when you think about a warming cup of tea: but then again, it's possible you're not reading Serious Eats from Tibet. The traditional blend of black tea, milk and salty yak butter, known as Po Cha, is as ubiquitous in the Himalayan regions as...well, as the yak itself. (And before we offend any yaks, we refer of course to the butter of his better half, the female, known as the "nak".)
A fortifying and sometimes controversial drink, this combination of tea and salty fat is thought to be ideal for the high, often cold altitudes of the Himalaya. Whether served socially—ladies refilling each others' cups of butter tea again and again—or as preparation before a hard, cold day's work, filling the body with butterfats and sodium. (Think of it as a caffeinated, somewhat more viscous, buttery, vaguely sour Gatorade. Or, you know...don't.)
And although the flavors are based around the essential pillars of black tea and milk, how quickly they take a turn. From the minute the savory concoction hits your lips, it confuses. Slightly astringent yet warm and buttery, you're initially warmed and then confused with butter and then confused again with black tea. The sting of salt is like having a drink of the ocean—which usually feels like a mistake. You get thirstier and thirstier, which is Po Cha's clever little game, and it may take a western palate hundreds of sips (or cups) to begin to make up their mind. Many never finish the first.
Nak's butter brings with it a much stronger taste than mass-marketed cow's milk butter. In more remote parts of the Himalaya, the butter may suffer enough from diverse storage conditions that it imparts a unique taste often described as "rancid" or "pungent". This particular slant to an otherwise comforting-sounding drink is part of its shock value to outsiders' palates. You may get a strong dose of earthiness from the tea as well, as many preparations rely on aged pu-erh teacakes, from either Tibet or China, to provide the strong black tea base.
Traditional preparation of Po Cha requires special equipment and a measure of patience. Once you've got your hands on a nak, you've got to make some butter. To form the base of the tea, black tea is steeped for several hours to form a concentrate known as chaku, which is then combined with the butter and salt in a tall cylindrical wooden churn until more or less smooth. Po Cha is served with milk, in decorative ceramic bowls, and topped up over and over again before you even get the chance to reach the bottom of a cup.
The salty-yak-butter-tea-curious in North America may be disappointed, however: though it's on the menu in many Tibetan restaurants, let's just say that the milk of the yak (or nak) is rather scarce in these parts. Cow's milk butter is substituted for nak butter, Lipton is substituted for pungent brick tea, and, a blender or espresso machine's steam wand will stand in for a traditional tall butter churn—in a pinch.
If you'd like to try your hand at Po Cha, you can make a general start with basic ingredients (assuming you don't have access to a nak). Boil 6 cups of water and steep a tablespoon of black tea in it for 5 minutes. Strain, add 2 tablespoons of butter, and blend in a blender with a quarter teaspoon of sea salt until well integrated. Serve with warm half-and-half, enjoy the salty goodness, and imagine how much better it would be with your nak.