For my fellow Sheffielders this is a common phrase among those who like Henderson's Relish (let's face it if you don't like it, then you aren't a Sheffield lad or lass)
A bottle of alcohol which is usually very cheap (Imperial Fortified Wine 750mL 20% alc $9.45) and is usually consumed by street people; who had gone and collected enough empty cans and bottles all day just to afford.