
Old Tom gin is a lightly sweetened style of gin — historically the bridge between malty Dutch genever and bone-dry London gin. It has no fixed legal definition, so how sweet it is (and whether it’s neutral-based or maltier and barrel-aged) varies by maker.
The difference from a dry gin is sugar and a rounder texture, and only the sugar is easy to put back: a barspoon of syrup per measure gets the sweetness and not the weight. Where the recipe is a Martinez or a Tom Collins, that softness is the reason the style exists.
London Dry may not be sweetened — no more than 0.1 g/L. The drink lands drier: on a recipe written for Old Tom, add back about a barspoon of syrup.
Genever is a maltier Dutch spirit on a malt-wine base with a heavier, grainy character; Old Tom is usually lighter and neutral-based. Pour genever into a Tom Collins and the drink turns bready and loses the light sweetness the style is built on.
"Old Tom is a brand"
It’s a style, not a distillery’s name — a lightly sweetened gin, made by many producers at different sweetness levels.

Ramos Gin Fizz
Old Tom gin

Singapore Sling (Old Tom Gin)
Old Tom gin

Tom Collins
Old Tom gin

Gin Sour
Old Tom gin

Tuxedo
Old Tom gin, Dry vermouth

Old Tom Gin
Old Tom gin

Alaska
Old Tom gin

Alaska (1914 recipe)
Old Tom gin

Turf Club
Old Tom gin, Rosso vermouth

Turf Club (1895 recipe)
Old Tom gin

Turf Club (1939 recipe)
Old Tom gin, London dry gin

Tuxedo Perfect
Old Tom gin

Chauncey
Old Tom gin, Rye whiskey, Rosso vermouth, Cognac

Gin Sangaree
Old Tom gin

Surf and Turf
London dry gin

Casino – IBA
Old Tom gin

Tuxedo – IBA
Old Tom gin, Dry vermouth