On a small plate, combine tajín and sea salt. Spread the chamoy sauce in a shallow dish or on another small plate. Moisten the glass rim with the meyer lemon zest or a cut lemon wedge, then dip the rim first into chamoy to get an even, thin coating and immediately press the rim into the tajín-salt mixture to create a spicy-sour rim. Set the glass aside to let the chamoy set slightly while you make the cocktail.

If using egg white for texture, chill the serving glass in the freezer briefly (optional).

Mixing the Cocktail

Dry shake (if using egg white)

In a cocktail shaker, add mezcal, meyer lemon juice, grapefruit juice, chamoy syrup, agave syrup and the egg white (if using). Perform a vigorous dry shake (no ice) for 15–20 seconds to emulsify and build foam.

Wet shake

Add a generous scoop of ice to the shaker and shake vigorously for 10–15 seconds until well chilled (shake until the outside of the shaker is frosty).

Double strain the cocktail into the prepared glass (old fashioned or rocks glass) over a large ice cube or fresh ice to remove any small ice shards and ensure a smooth texture.

Finish & Garnish

If desired, lightly float a few drops of chamoy or a tiny sprinkle (a pinch) of smoked paprika on the foam or surface for aroma and visual contrast. Alternatively, float 1/4 tsp of mezcal by pouring it over the back of a spoon to sit on top for an extra smoky note.

Garnish with a thin wheel or twist of meyer lemon placed on the rim or floated on the surface. Serve immediately.