0.8 oz × 29.57 ml × 0.789 g/ml = 19 g · about 130 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.
The bitter from gentian root, used across Campari, Aperol, sweet vermouth, Angostura, and most amari. Bitter compounds activate TAS2R taste receptors that evolved to detect plant alkaloids. The same machinery that makes broccoli taste bad to children also makes a Negroni taste like an adult ordered it.
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.
The Bronx with Angostura bitters. It is a small addition that shifts the profile from citrus-forward to spice-forward, as the bark and clove of Angostura anchor the fruit juice. Named for the 1913 Sixteenth Amendment.
PROVENANCE
First documented in Harry Craddock's 1930 Savoy Cocktail Book. The name is generally taken to refer to the 1913 ratification of the 16th Amendment to the US Constitution, which established the federal income tax, a then-recent grievance that bartenders memorialized in a cocktail. Craddock printed it in full (gin, both vermouths, orange juice and a dash of Angostura), a Bronx with bitters in all but name.