(or just blitz granulated sugar in a blender until finely ground but not powdery; omit if using Old Tom gin)
fresh lemon juice
London dry gin or Old Tom gin
(such as Hayman’s)
or more, as needed
Dump the sugar and lemon juice in a Collins glass or other tall, narrow glass. Stir to dissolve the sugar, then add the gin, several ice cubes, and soda water and mix gently to combine.
Submerge the lemon zest in the glass so it spirals around the ice cubes. We think you know what to do from here...