Place the hulled and quartered fresh strawberries in a blender or food processor. Add 1/2 fl oz of the simple syrup (from the total) to help the fruit blend smoothly. Pulse until you have a smooth purée (about 20–30 seconds). If you prefer a smoother texture, strain the purée through a fine mesh sieve into a bowl, pressing with a spatula to extract as much liquid as possible. Reserve the purée and any strained juice.

Build the punch base

In a large pitcher (about 1.5–2 liters capacity), combine the pisco (8 fl oz), the prepared strawberry purée (all), the fresh lemon juice (3 fl oz), fresh lime juice (1 fl oz), and the remaining 1.5 fl oz of simple syrup. If you kept the 0.5 fl oz for blending, make sure total simple syrup added equals 2 fl oz. Stir thoroughly to combine so the citrus and syrup integrate with the pisco and purée.

Incorporate egg white (optional)

If using an egg white for a silky foam, add the egg white to a cocktail shaker with 4–6 oz of the punch mixture (or a few ounces of ice-free punch). Perform a dry shake (no ice) vigorously for 15–20 seconds to emulsify and create foam. Then add ice and shake again 10–12 seconds to chill. Pour the shaken mixture back into the pitcher and stir gently to incorporate the foam. (If avoiding raw egg, omit this step.)

Chill and add sparkling water

Add crushed ice to the pitcher or directly to serving glasses. Pour the chilled sparkling water (12 fl oz) into the pitcher and stir gently once to combine; this preserves carbonation while mixing the punch. Taste and adjust: if the punch is too tart, add up to 0.5 fl oz more simple syrup; if too sweet, add a splash more lemon juice (up to 0.25 fl oz).

Serve

Fill six highball or punch glasses with crushed ice (about 1 cup each). Pour the Strawberry Pisco Punch evenly among the six glasses (roughly 6–7 fl oz per glass). Garnish each glass with a strawberry slice on the rim, a lemon wheel, and a sprig of fresh mint. Add a couple of dashes of Angostura bitters over the foam or on top of each glass (approximately 1 dash per glass; total 6 dashes).

Storage and notes

If not serving immediately, keep the prepared punch base (without sparkling water) refrigerated up to 24 hours; add sparkling water and ice just before serving. If using pasteurized egg white substitute or aquafaba, adjust quantities to yield similar foam volume (about 2 tablespoons aquafaba per egg white).