Pisco sour — the national cocktail of Peru, made from pisco (grape brandy), fresh lime juice, simple syrup, egg white, and Angostura bitters — requires a specific technique to produce its characteristic thick, stable white foam on the surface. The egg white foam is not simply shaken — it requires a "dry shake" (shaking without ice to aerate the egg protein) followed by a wet shake (with ice to chill and dilute) to produce the stable foam that defines the preparation.
- **Dry shake first:** All ingredients except ice shaken vigorously for 15–20 seconds. The absence of ice allows the egg white proteins to unfold and begin forming a foam network — ice would inhibit this by chilling the proteins before they can aerate. - **Wet shake second:** Ice added, shaken briefly — 5–10 seconds. The ice chills the drink and dilutes it to the correct concentration without breaking the foam structure already developed. - **Pisco:** Peruvian pisco is different from Chilean pisco in production method and grape varieties — unaged, single-distillation, made from specific Peruvian grape varieties (Quebranta, Italia, Torontel). [VERIFY] Acurio's pisco specification. - **Lime:** Fresh-squeezed only. The volatile esters that give Peruvian lime (limón sutil) its character are absent from bottled juice. - **The bitters:** Three drops of Angostura on the foam's surface — decorative and aromatic. The bitters' volatile aromatic compounds are encountered by the nose before the palate.
Peru