Water

Water is an extremely common liquid. It can be produced anywhere using Well or Water Generator. It also exists on Arctic oceans in infinite quantities, and also on 50% of Dark Arctic oceans (others have Salt Water instead).

It's notable for being usable for watering plants and for being a part of many mixing recipes (something+Water = something else).

Water plays an important role in infinite mixing of several other liquids, including Poison, Healing Water, Sulphuric Acid and Organic Soup.