Cheap liquor is a consumable item, available in Risen 2 and 3. When consumed, cheap liquor increases a character's blood by 25. This means that 25 points of health will be instantly restored. In Risen 3, if Ultra Combat Difficulty is used, a cooldown of approximately 10 seconds is applied after drinking this item.
Cheap liquor (probably because it's cheap) can be found frequently. It can be bought from merchants like Hawkins and Spencer. It can be found in chests. It can even occasionally be found sitting on top of a shelf or table.