Plymouth Sloe Gin—like all sloe gins—is not technically a gin but rather a liqueur made with sloe berries. Plymouth Sloe is made from a recipe from 1883 where the berries are steeped in the original gin with a bit of sugar for sweetness. They suggest serving neat as accompaniment to dessert.
Plymouth Gin has been in production since 1793. In modern times, the grain alcohol is made at Blackfriars Distillery, which itself dates from the 15th century. Today, Blackfriars is owned by Coats Distillery, home of Plymouth gin.
The label is now owned by Pernod-Ricard as part of a merger in 2008.