The classic martini is typically made by mixing 2.5 oz gin with 0.5 oz dry vermouth, resulting in a 5:1 ratio by volume, which yields a cocktail with approximately 30–32% alcohol by volume (ABV) after dilution from stirring with ice. This ratio balances the strong flavor and alcohol content of gin with the aromatics of vermouth, and dilution from ice is essential for proper taste and mouthfeel.

• • Standard recipe: 2.5 oz gin + 0.5 oz dry vermouth (5:1 ratio)

  • Final ABV (after stirring/dilution): ~30–32%

  • Typical total volume (after dilution): ~3.0–3.2 oz

  Note: Adjusting the gin:vermouth ratio or stirring time changes the strength and flavor profile.

Primary Output

The canonical martini uses a 5:1 gin to vermouth ratio by volume, resulting in a cocktail with approximately 30–32% ABV after accounting for typical dilution from ice during stirring.

Variables

• G = volume of gin (oz)

• V = volume of dry vermouth (oz)

• R = ratio of gin to vermouth (G:V)

• ABV_gin = alcohol by volume of gin (typically 40% = 0.40)

• ABV_vermouth = alcohol by volume of dry vermouth (typically 16% = 0.16)

• D = dilution factor (fractional increase in total volume from melted ice, typically 20–30%)

• V_total = total volume after dilution (oz)

• ABV_final = final alcohol by volume of the cocktail (%)

Known Inputs

• G = 2.5 oz

• V = 0.5 oz

• ABV_gin = 0.40

• ABV_vermouth = 0.16

• D = 0.20 (20% dilution, typical for stirred cocktails)

Assumptions

• All volumes are additive (no significant contraction upon mixing).

• Dilution from ice is 20% of the initial liquid volume.

• No significant alcohol evaporation during stirring.

Governing Equations

V_{initial} = G + V

V_{total} = V_{initial} × (1 + D)

Alcohol_{total} = G × ABV_{gin} + V × ABV_{vermouth}

ABV_{final} = Alcohol_{total} / V_{total}

Calculation Steps

V_{initial} = 2.5 + 0.5 = 3.0\ \text{oz}

V_{total} = 3.0 × (1 + 0.20) = 3.0 × 1.20 = 3.6\ \text{oz}

Alcohol_{total} = 2.5 × 0.40 + 0.5 × 0.16 = 1.0 + 0.08 = 1.08\ \text{oz}

ABV_{final} = 1.08 / 3.6 = 0.30 = 30\%

If dilution is only 10% (D = 0.10):

V_{total} = 3.0 × 1.10 = 3.3\ \text{oz}

ABV_{final} = 1.08 / 3.3 ≈ 0.327 = 32.7\%

Sensitivity

• Increasing vermouth (e.g., 2:1 ratio) lowers ABV and increases aromatics.

• More dilution (longer stirring) lowers ABV and softens flavor.

• Using vodka (40% ABV) instead of gin yields similar math.