3.06 oz mixed with ice, 0.92 oz of it pure alcohol
Melt
Shaken: +20 % of the pre-batch, +0.61 oz of water
Served
3.06 + 0.61 = 3.67 oz in the glass
Strength
0.92 ÷ 3.67 = 25.1 % ABV as served
Ethanol
0.92 oz × 29.57 ml × 0.789 g/ml = 21 g · about 150 kcal from the alcohol alone
IN THE GLASS
α-PINENE
FROM GIN
Formula
C₁₀H₁₆
Mass
136.24 g/mol
IUPAC
2,6,6-trimethylbicyclo[3.1.1]hept-2-ene
The pine note in juniper berries, and the reason gin tastes like a forest. Co-distilled with the spirit during production. Found in actual pine trees, rosemary, basil, and a good London Dry. The "Christmas tree" smell of gin and the smell of a forest floor share a single molecule.
An orange rind, squeezed, throws a spray that catches the light. That's d-limonene boiling off. It's roughly 95% of orange peel oil by mass, and the molecule that puts the "orange" in orange anything. Used industrially as a green solvent because the chemistry that dissolves citrus oils also dissolves greasy machinery. The expressed-peel garnish on a cocktail is delivering vaporized limonene to the rim of the glass.
Lemon's defining note: technically a mix of two geometric isomers (geranial and neral) that read as the same aroma to the nose. Lemon peel, lemongrass, lemon verbena, and Indian chai all carry it. In cocktails it's what a lemon twist contributes that lemon juice can't: the volatile expressed from the oil glands, not the acid from the pulp.
Gin, orange curaçao, lime and two bitters. Alpha-pinene from gin and d-limonene from curaçao stack into a two-layered pine-and-citrus nose, and Angostura's bark and clove backbone adds depth.
PROVENANCE
Created at the Pegu Club, the British officers' bar in colonial Rangoon (modern Yangon, Myanmar). Harry Craddock's 1930 Savoy Cocktail Book describes it as the club's favorite, 'one that has travelled, and is asked for, round the world.' The drink fell into obscurity after Burmese independence; Audrey Saunders revived it as the namesake of her acclaimed Manhattan bar Pegu Club, which ran from 2005 to 2020.