It's refreshing, delicious, and contains 3.6 grams of protein (the amount in an egg white according to the U.S. Dept. of Agriculture).

Pisco is a grape brandy from either Peru or Chile.  If you saw the post about torched Dutch grapes (click here to read it), you learned that brandy can come from anywhere.  Both Peru and Chile insist that pisco and the Pisco Sour belong to their respective countries.  In 2013 the United States recognized pisco as a unique product of either country (in exchange they recognized bourbon and Tennessee whiskey as unique American products).

The Pisco Sour is the most famous of pisco cocktails.  Interestingly, just as an American in Cuba created the Daiquiri, an American in Peru created the Pisco Sour.   

2 ounces pisco
Juice from 1/2 lime
1 ounce super simple syrup
1 egg white
3-4 dashes Angostura bitters

Combine everything but the bitters in a shaker, shake as if you're bolting up the mountain towards Machu Picchu (this is dry shaking because there's no ice), add ice, shake again (now you're wet shaking), strain into a chilled cocktail glass, and add the bitters into the foam.

Pisco is popular enough that you can get it in liquor stores. If you order a Pisco Sour in a bar you may have to ask the bartender to add the bitters.  Not only are the bitters visually appealing, but they give the drink a nice little twist.  

I'm not going to weigh in on whether Peru or Chile has the right to claim exclusive ownership of pisco.  So which version of the Pisco Sour do I prefer?  My research indicates that the Peruvian version has egg white and bitters, but the Chilean version does not.  I love protein, so I'm going with Peru on this one.  Hope that doesn't make me persona non grata in Chile.