Place the mixed fresh berries and 0.5 tbs granulated sugar in a small bowl. Gently muddle with a spoon or muddler until the berries begin to break down and release juice (about 30–45 seconds). Let sit 5 minutes to macerate. Transfer to a fine-mesh sieve set over a bowl and press with the back of a spoon to extract roughly 2 tablespoons (≈0.75 oz) of purée/juice. Discard solids or reserve for garnish.

If you prefer a chunkier texture, skip straining and use the smashed berries directly in the shaker (you may want to double-strain later). Stir in lemon zest if using.

Cocktail

Dry Shake (if using egg white)

In a cocktail shaker add the fruit purée (about 2 tablespoons), 2 oz gin (or vodka), 0.75 oz fresh lemon juice, 0.75 oz simple syrup, 0.5 oz berry liqueur (or raspberry syrup), and the egg white. Dry shake vigorously (no ice) for 12–15 seconds to emulsify and create foam.

Wet Shake

Add a large handful of ice to the shaker. Shake vigorously for 12–15 seconds until well chilled and the shaker is frosty.

Double-strain the cocktail into a chilled rocks glass filled with fresh ice (use a fine strainer if you didn't strain the purée earlier to remove seeds and pulp).

Finish & Garnish

Top the drink with about 1.5 oz club soda to lighten and give effervescence. Gently stir once with a bar spoon to combine without flattening the foam.

Garnish with a lemon wheel and 3 fresh berries on a pick or floated on top. Serve immediately.