Sloe gin is a red liqueur made with gin and sloe berries. Sloes are the fruit (drupe) of Prunus spinosa, the blackthorn plant, a relative of the plum. The difference between the Gin and Sloe Gin - The main ingredient of sloe gin is the sloe berry and gin is derived from the juniper berry. Sloe gin can have a lower alcohol content than gin. Gin is less sweet than sloe gin. Gin is made from traditional distillation processes while sloe gin is made from mixing sugar and sloe berries and steeping in gin.