Lava Farm
Intermediate Different design per edition
Produces: Infinite lava in cauldrons - one full bucket per cauldron per refill cycle
Quick answer: A pointed dripstone stalactite under a lava source slowly fills an empty cauldron with lava: 15/256 chance per random tick, about once every ~19 minutes per module on average. A row of modules makes lava a renewable fuel.
How it works
- The recipe: a lava source on top, a solid block under it, a pointed dripstone hanging from that block, and an empty cauldron below within 10 blocks of the tip. In the Nether the lava source is not needed.
- Each random tick on the top of the stalactite rolls a 15/256 chance (~5.9%) to completely fill an empty cauldron with lava - averaging roughly one Minecraft day (19+ minutes) per refill, per setup.
- Water works too: a water source above fills the cauldron one level at a time (three levels per bucket) at ~17.6% per tick - but lava is the prize, since it fills the whole cauldron in one drip.
- The lava and water sources are never consumed - one bucket of lava fuels an unlimited number of buckets out.
- Lava buckets smelt 100 items each, so a modest farm out-fuels any coal supply; this is the mid-game furnace upgrade.
Materials
- Pointed dripstone (dripstone caves) - one per module
- Dripstone blocks or any solid blocks for the ceiling
- Lava buckets - one per module, never consumed
- Cauldrons (7 iron each) - as many as you can afford
- Fireproof building blocks (no wood near lava)
Build steps
- Find pointed dripstone: dripstone caves are everywhere under mountains - harvest the tips with any tool.
- Build the ceiling row: solid blocks in a line, one lava source on top of each, contained so it cannot flow off.
- Hang one pointed dripstone under each block.
- Place a cauldron under every dripstone, with clear air between tip and cauldron.
- Walk away: each module averages a full cauldron per Minecraft day - twenty modules average a bucket about every minute.
- Harvest with empty buckets; cauldrons refill on their own forever.
- Keep the area loaded: random ticks run only near players, so build it where you spend time.
- Scale by rows: modules stack vertically too (cauldron, air, next ceiling) for tower designs.
Rates
One module averages a lava bucket every ~19 minutes; a 20-cauldron array yields roughly a bucket a minute while loaded - free fuel for every furnace, blast furnace and smoker you own.
Tips
- Iron is the real cost: 7 ingots per cauldron, so grow the array as your iron farm grows.
- Keep anything you do not want burned away from the lava row.
- The cauldron must be within 10 blocks of the stalactite tip.
- Mark empty cauldrons: hoppers cannot extract lava, so harvesting is manual - a walkway makes rounds fast.
- Source: minecraft.wiki Lava.