Water Cauldron is the Java Edition block state of a Cauldron filled with water, created not on a crafting grid but by using a Water Bucket on a placed empty Cauldron in Minecraft. One Water Bucket fills the cauldron to its maximum — 3 levels in Java Edition and 6 levels in Bedrock Edition, where the base Cauldron block stores the water as a data value instead of using a separate ID. A Water Bottle adds 1 level in Java Edition (2 in Bedrock), a Glass Bottle removes 1 level (2 in Bedrock), and slow rainfall or water dripping from a Pointed Dripstone placed under a water source tops the fill up over time. Water Cauldron was split off as its own block ID in Java Edition 1.17 (snapshot 20w45a) during The Flattening, has a hardness of 2 and a blast resistance of 2, and a pickaxe is required to mine and drop Water Cauldron — mining without a pickaxe yields no drop at all.

Pressing use with dyed Leather Armor, Leather Horse Armor, Wolf Armor, a Shulker Box, or a Banner in hand washes the topmost banner pattern layer or the dye out of the item, and each wash removes one water level from Water Cauldron. Burning entities that fall in are extinguished at the cost of one level, and flaming arrows that land in the water are put out in Java Edition. A Redstone Comparator reads the fill and outputs signal strength 0, 1, 2, or 3, turning Water Cauldron into a silent fluid-level sensor for hidden doors and farms. Bedrock Edition adds two extras the Java block cannot do: water inside can be dyed one color at a time, and Potions can be stored at 2 levels each to turn arrows fired into the cauldron into tipped arrows. Water Cauldron is renewable (the empty Cauldron is crafted from 7 Iron Ingots, and iron is renewable via Iron Golems and zombies), stacks to 64, and suits dye stations, potion labs, and redstone workshops where a contained water source never floods the room.