Notes on The Gin Fizz
The Gin Fizz is one of the IBA’s official gin cocktails. The combination of gin, citrus, some form of sugar, and seltzer dates back to at least 1882’s Harry Johnson’s New and Improved Bartender’s Manual.
Johnson’s recipe calls for Old Tom Gin; however, as tastes changed over the next thirty years, we’d see the Old Tom slowly replaced with dry (unsweetened gin). Given that the Gin Fizz adds some sort of sweetening syrup already, I don’t think the sweeter gin is necessarily needed. Unless you’re going for historical accuracy.
And speaking of historical accuracy the seltzer component of the original might be somewhat different from what you might expect. William Bernhard described the flavor of effervescing beverages in his 1850 edition of The Book of One Hundred Beverages as a “cooling saline beverage.” The fizzy waters of the time were a bit more like club soda than what we call seltzer or soda water today. In the modern day if you make a gin fizz or order a gin fizz out, it’s likely you’re going to get one with plain soda.