
Sloe gin is a red fruit liqueur made by steeping sloes, the fruit of the blackthorn, in gin with sugar; despite its name it is a liqueur, not a gin.
A ripe, plummy blackthorn-fruit aroma leads into a sweet, red-fruit body with a soft almond-like edge and low acidity and bitterness.
Used as a sweet fruit modifier, poured in measures that both flavour and colour a drink; it carries high sweetness and body, so it is dosed to balance sharper or drier components rather than as a base measure.
Where it is only a flavouring accent, another red fruit liqueur can stand in — matching its colour and topping up sweetness with simple syrup and strength with a touch of gin or neutral spirit. But the specific sloe/blackthorn aroma is species-specific: where sloe gin is the featured ingredient, only a closely related sloe-based liqueur will preserve the drink's identity.
Gin
Sloe gin is a sweetened fruit liqueur (EU minimum 25% ABV) flavoured with sloes, not a juniper-forward distilled spirit; it is the one liqueur legally permitted to use the name 'gin'.
Pacharán
Pacharán is a Navarran sloe liqueur flavoured with aniseed and typically 25–30% ABV, whereas sloe gin is a British gin-based sloe liqueur with no anise character.
Sloes — the drupe fruit of the blackthorn (Prunus spinosa), a relative of the plum — are macerated whole with sugar in a gin base, a post-distillation infusion rather than a redistillation, which draws out the fruit's colour and character. The result is a red-coloured liqueur that commercially typically runs between about 15% and 30% ABV. Under EU rules 'sloe gin' is a permitted legal name, making it an exceptional case where a liqueur may carry the word 'gin'.
Sloe gin is a British liqueur, most famously made in England, where sloe berries have been steeped in gin with sugar for centuries.

Sloe Gin Fizz
Dry sparkling wine, Sloe gin

Slow Negroni
London dry gin, Sloe gin, Red bitter

Alabama Slammer Shot
Amaretto liqueur, Southern / Louisiana-style whisky liqueur, Sloe gin

Alabama Slammer
Vodka, Southern / Louisiana-style whisky liqueur

Sloe Gin Cocktail
Sloe gin

Charlie Chaplin
Apricot brandy liqueur, Sloe gin

Slow Comfortable Screw Between The Sheets
Vodka, White rum, Cognac, Southern / Louisiana-style whisky liqueur, Sloe gin

Red Rum Martini
Caribbean aged rum