Pre-chill a coupe glass. Prepare a lemon zest twist and have aromatic bitters ready for garnish.
Combine rye whiskey, fresh lemon juice, rich sugar syrup, absinthe, and egg white in a shaker.
Add ice and shake hard for 10–12 seconds (wet shake).
Strain the liquid back into the shaker tin, discarding the ice.
Dry shake vigorously without ice for 15–20 seconds to build a thick, aerated foam.
Fine strain into the chilled coupe glass.
Express the lemon zest twist over the surface of the drink to release its oils, then discard.
Finish by dashing aromatic bitters onto the foam and drawing a cocktail pick or straw through the dashes in an S-shape to create a snake pattern.
The reverse dry-shake technique - wet shake first, then discard ice and dry shake - produces a denser, more stable foam than dry shaking first, because the chilled liquid emulsifies the egg white more effectively before aeration.
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