Autumn is upon us again. Which means, this year, it’s time for some mathematics! Let’s contemplate ratios and sequences for a moment. The ratio when a+b / a = a/b, for example, is known as the “Golden Ratio” and has a perfectly balanced proportion, pleasing to the eye, that has been used throughout art and culture. For example, the Mona Lisa’s face is proportioned in the Golden Ratio. As for sequences, and speaking of the Mona Lisa, there is a famous numerical sequence known as the “Fibonacci Sequence” which also makes an appearance in the Da Vinci Code. It’s directly related to the Golden Ratio as well. That’s all well and good for ancient codes and pleasing art and architecture, but what does it have to do with cocktails?

Philadelphia mixologist and head bartender at Friday Saturday Sunday Paul MacDonald has a few claims to fame. One of them is his invention of the “Fibonacci Cocktail”. Cocktails in general rely on certain proper ratios of spirit, citrus, sweetener and modifying agents to make a well balanced drink. Ratios such a 2:1:1, 1:1:1, 8:2:1 and others are part of the canon. MacDonald thought he could extend the idea to incorporate a Fibonacci ratio, using his ingredients in a 1:1:2:3:5 proportion. It makes a lot of sense for cocktails too, and he has come up with a “number” of fantastic drinks which showcase the concept.

One of my favorites is his Fibonacci in Autumn, and I’ve been waiting for months to feature this drink. The time has come! The five ingredients used, in a Golden ratio, are Cocchi Americano, Cappeletti Aperitivo, Laird’s 100 Apple Brandy, Green Chartreuse and Amaro Nardini. The flavors build from lighter in flavor profile to heavier, and are balanced by cutting the volume of the richer, darker and more potent flavors as the sequence progresses. There is a lot going on here, with two Italian Amari, the intensely herbal liqueur Chartreuse, and the aromatic infused Cocchi, anchored by a sturdy apple brandy. But, as expected, it works in a harmoniously golden way. I managed to substitute a few like-minded spirits from my cabinet – Amaro Averna for the Nardini, and Meletti for the Cappeletti – and everything still worked perfectly. It’s an incredibly delicious drink, a perfect fall sip and a stunning crowd pleaser that’s sure to impress your guests. Especially if you set it all up separately and then mix it all together. Here’s to the golden days of autumn. Cheers!

Fibonacci in Autumn by Paul MacDonald

¼ oz Amaro Nardini

¼ oz Green Chartreuse

½ oz Laird’s 100 Apple Brandy

¾ oz Cappeletti Aperitivo

1 ¼ oz Cocchi Americano

Stir with ice and strain into a favorite glass. Garnish with a perfectly proportioned citrus spiral.

For more from about the Golden Ratio puzzle box see:

Boxes and Booze: Good as Gold