In a sour cocktail, we add an egg white so that when shaken with the gin and some lemon juice in a cocktail shaker the egg froths up into a nice creamy foam. We pour the drink through a small strainer and this gives a bit of height to the foam, helps mellow it out and adds a nice texture.
60 ml Orginal Biggar gin
22 ml simple syrup
30 ml grapefruit juice
30 ml lemon juice
1 egg white (this can be substituted for aquafaba - the juice in cans of chickpeas)
Combine all ingredients with plenty of ice in a cocktail shaker
Shake hard to chill the drink, provide some dilution from the ice and create the foam.
(Top tip - to get extra height on the foam we shake with ice to chill the drink, then remove the ice and shake again)