The John Collins was originally made with aromatic Dutch genever. Genever was
a popular drink among Londoners until taxation and import restrictions made it
hard to obtain, so London Dry Gin became the ingredient of choice. The
cocktail was named after its inventor, John Collins, who was a headwaiter at
the Limmer’s hotel & coffee house, on Conduit street.
http://www.beefeatergin.com/mixology/video.php?video=John%20Collins
2 PARTS Beefeater London Dry Gin
1 PART Fresh lemon juice
3 BARSPOONS Castor sugar
BUILD Ingredients into a Catalina glass over crushed ice and churn
TOP UP Soda water
FINISH With another topping of crushed ice
GARNISH With 2 lemon slices and serve with 2 straws