The bartender took out a chilled glass, separated the egg whites into a tin and then measured and added the lime, pisco and simple syrup and shook the cocktail into a froth. As he poured, the white drink toppled into the glass, the lime and pisco separating to the bottom. "Pisco hasn't been very popular in New York City," he said. "But now people are learning more about it." He finished the drink with a dash of Angostura bitters and placed it before me.