Unbeknownst to many mixers, nearly every cocktail can be classified as a member of a larger family of recipes derived from a canonical elemental mother formula. Every time I create a new one, I'm careful to consider all known variations upon a theme within the family I choose to improvise upon—quite a task considering the history of each family of mixed drinks!
Recently, when a fresh parcel of lemon basil appeared at the bar, I thought about all the herbs I've incorporated into my recipes over the years. Aside from mint, which is used year-round behind the bar, I typically mix with dill and cilantro in the spring, shiso and tarragon in the summer, oregano and sage in the fall, and rosemary—if any herbs at all—in the winter.
Mixing with fresh herbs, except for mint, is a somewhat recent innovation: You'd be hard-pressed to find classic cocktails using a kitchen staple like basil dating back to the 19th Century, but there have been some really interesting ones over the past decade, as more and more bartenders started incorporating culinary ingredients into drinks.
But getting back to my lemon basil parcel: My favorite basil cocktail of all time is Phil Ward's Little Jig, a recipe dating back to our days working together under Audrey Saunders at NYC's Pegu Club. It's a refreshing combination of tequila, lime juice, Yellow Chartreuse, simple syrup and Thai basil. Phil named it the L'il Jig because all of the ingredients could be mixed using the smaller of two jiggers we used to measure every drink there.
Thinking about how spicy Chartreuse and savory Thai basil enhance characteristics of the earthy tequila in the Little Jig, I used Phil's recipe as a template for improvistation with lemon basil (see the recipe). Naturally, lemon juice is a much better pairing than lime for the lemon basil, and Irish whiskey offers a bright, bready quality, that just so happened to work well with Yellow Chartreuse. A taxonomist at heart, I couldn't stop myself from calling it the Irish Jig—this time, for the whiskey and the dance, not the jigger.
As far as incorporating summer herbs into your cocktails, lemon basil is a dream! It's aromatic, pairs well with citrus and is much less vegetal than its ubiquitous cousin, but it still packs plenty of pepper.
For these reasons, I wouldn't exchange it with any other type of basil in the Irish Jig—which I made specifically for lemon basil. So if all you can get your hands on is Thai basil, make a L'il Jig instead. Both drinks use the same proportions, just with different liquor, citrus and sweetener in my Irish predecessor.