The Manhattan is the second-easiest cocktail to batch (after the Negroni) and the one most worth doing. The drink's three core components — rye, sweet vermouth, Angostura bitters — are all shelf-stable for months refrigerated. The 2:1 ratio is fixed and well-loved. And the bartender's stir is the only thing the bottle replaces, so the conversion costs nothing the customer can taste in a blind pour.
A Manhattan you can pour in eight seconds is a Manhattan you can sell on a Friday night.
— Service-bar maximThe 2:1 ratio holds at scale
Two parts rye, one part sweet vermouth, a generous dash of Angostura per drink. The ratio is the drink — change it and you have something else. At service the proportions are stirred in the mixing glass; in the bottle they're combined neat with a measured shot of water to mimic the stir's dilution.
Pick the rye carefully. The bottle will sit refrigerated for weeks; the rye sets the floor of the drink. Rittenhouse Bottled-in-Bond is the workhorse choice; if the budget allows, a higher-rye like Sazerac 18 or a Willett rye lifts the bottle considerably. For the vermouth: Carpano Antica Formula or Cocchi di Torino. The drink lives or dies on the vermouth more than on the whiskey.
Dilution: 18 percent water
A fresh-stirred Manhattan picks up about 22 to 25 percent water from the ice across a long stir. A bottled Manhattan poured over a large rock will continue diluting at service, so the bottle's pre-dilution is lower: 18 percent filtered water by total volume. The math for a 750ml bottle at eight pours: 530 ml of spirits (rye + vermouth in 2:1), 135 ml of water, plus a teaspoon of Angostura.
Stir gently as you combine — you're not aerating, you're integrating. Cap, refrigerate at least two hours, ideally overnight. The cold itself finishes the integration.
Service
Invert once, pour 3.1 oz over a single large cube in a rocks glass. Garnish with a brandied cherry; an orange peel is optional and traditionally Italian. The drink reads exactly like a fresh stir — slightly cooler at the mouth, slightly more uniform from sip to sip.
Refrigerated, the bottle holds 60 days without measurable degradation; the vermouth's sweetness softens slightly over time but in a way that helps, not hurts.