Fibonacci in Autumn by Paul MacDonald

To toast the Golden Ratio box we need to continue along the mathematical theme, and introduce another famous construct “discovered” by a thirteenth century Italian fellow with a preoccupation for rabbit reproduction. He put the theoretical sequence of rabbit population expansion down on paper, explaining how it followed a pattern where each subsequent rabbit pair would be the sum of the prior two. Starting at 1 the “Fibonacci” sequence is: 1,1,2,3,5,8,13,21 etc …. Unbeknownst to Fibonacci, this sequence is directly related to the Golden Ratio. Dividing each number in the sequence by the prior number quickly approaches a certain ratio as follows: 1/1 = 1, 2/1 = 2, 3/2 = 1.5, 5/3 = 1.666…, 8/5 = 1.6, etc.. The ratio of the numbers in the Fibonacci sequence are an ever closer approximation of the Golden Ratio.

A surprising mix of diverse spirits

Whew! We deserve a drink after all that math. There was actually a point to introducing the Fibonacci sequence here, and we are getting to it now. 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.

A beautiful array of flavors and colors, like fall foliage, in the perfect ratio

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, Cappelletti 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 Cappelletti – 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!

I have an irrational fondness for this pair

Fibonacci in Autumn by Paul MacDonald

¼ oz Amaro Nardini

¼ oz Green Chartreuse

½ oz Laird’s 100 Apple Brandy

¾ oz Cappelletti Aperitivo

1 ¼ oz Cocchi Americano

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