If you want to start an argument, as a Peruvian and a Chilean standing in the same room who invented Pisco. Of course it is an irrelevant question because both countries love Pisco which is the generic name for unnamed brandies made in South America. Just like anything else there are good Pisco and not so good Pisco, so taste and research before you purchase.
The Pisco sour is basically just another sour like a margarita, daiquiri or whisky sour just made with another spirit, but it sounds so modern compared to those other cocktails. The main difference here is the ratio is much higher alcohol than in those, so a “balanced” Pisco sour will have more alcohol burn than its cousins which makes the quality of the pisco even more important than other bases.
Ingredients
3 ounces Pisco (I think this was originally made with Absolut Citron but I cannot confirm)
1 ounce lime juice
1/2 ounce simple syrup
egg white
Angostura Bitters
Garnish
Lime twist.
Glassware
5 oz coup or cocktail glass
Assembly
Chill a cocktail glass. Measure and add lime juice, simple syrup and egg white and shake to emulsify. Fill cocktail shaker with ice and add Pisco. Shake until chilled. Strain into cocktail glass and Put a dash across the foam on top.
Suggestions
Pisco is just as varied as the wines that they are based from. I like this with more aromatic varieties like Don Cesar makes a great Pisco from Moscato, which is why I do not add the Pisco until the chilling portion.