0.89 oz × 29.57 ml × 0.789 g/ml = 21 g · about 145 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 toasted-almond / caramel note in aged port, madeira, and amontillado sherry, formed when sugars in the wine slowly oxidize during long oxidative cask aging. Also in roasted coffee, baked bread, and any food that's been browned through Maillard chemistry. The deeper the toast on a bourbon barrel, the more furfural extracts into the spirit; the longer the madeira sits in the estufa, the more accumulates.
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.
The Vesper with a sour treatment. The Bond cocktail is converted from a stirred Martini to a shaken sour, with alpha-pinene from gin, Lillet's quinine-bittered wine and an egg white foam. A 2010s craft-bar invention.
PROVENANCE
An invented variation that takes the Vesper Martini's component spirits and rebuilds them as a sour. The Vesper Sour emerged at multiple American craft bars around 2012 as the cocktail world was in 'sour-everything' mode. The egg-white treatment softens the Vesper's hard edges; whether this counts as an improvement depends on the drinker's taste. Ian Fleming would probably not approve, but he wasn't a working bartender.