In my latest post for Popular Science, I wrote about the Sour cocktail category and how when you understand the basic format, you can make zillions of cocktails in that style.
When writing the story I had a fun and interesting debate on Facebook about how one defines a sour. To some people, a sour is a drink that contains spirit, citrus, sweetener, and egg white. But that was how the sour appeared at one point in time. At another point, the sour always used lemon juice and not lime.
I took the broader view, calling a Sour a cocktail with a base, a sour component, and a sweet component. So technically you could muddle Sour Patch Kids and NutraSweet in a glass of vodka and call it done.
But please don't do that. Instead, spend your time clicking over to PopSci.com to read the story.