How to Make a Cobblestone Generator in Minecraft

Cobblestone is infinite in Minecraft, and not because the world is big. Lava and water create it out of nothing when they touch in the right way, and a cobblestone generator is just a trench that arranges that meeting on repeat. It's a five-minute build with two buckets, and on SkyBlock it's literally the machine your whole world depends on.

The Rules You're Exploiting

That middle row is why some designs are called stone generators — same family of machine, different arrangement. The third row is the one that ruins beginners' day, because a mis-poured bucket turns your only lava into obsidian and ends the experiment.

The Simple Trench Generator

You need one bucket of water (or an ice block, which melts into water when broken) and one bucket of lava.

1. Dig a trench 4 blocks long, 1 wide and 1 deep.
2. Dig the second block from one end one block deeper, making a small pit inside the trench.
3. Pour water into the end nearest the pit. It flows along and drops into the pit instead of crossing the whole trench.
4. Pour lava into the far end. It flows toward the water, meets the flow one block short of the pit, and forms cobblestone there.

Mine the block, and the flows immediately make another. The pit is the entire trick: it traps the water so it can never reach the lava source and turn it to obsidian.

Upgrades Worth Knowing About

Collection designs

The popular step up routes the generated blocks over a line of hoppers into a double chest, using waterlogged stairs to shape the flows. You stand in one spot, hold down the mouse, and the chest fills itself — no more chasing stray cobblestone that popped into the lava.

Piston pushers

A more advanced layout detects each new block with a redstone torch and a piston, shoving the cobblestone into a row that a bank of pistons pushes toward you. You mine a continuous wall of stone without moving, and additional modules can be stacked around your position.

Fully automatic

The endgame version pushes cobblestone into the blast zone of a TNT duper on a timer, so the machine mines itself and hoppers collect the drops. It costs observers, sticky pistons, slime blocks and a lot of patience — build it once to say you did.

Java vs. Bedrock Notes

The trench design works identically on both editions, and it's the version worth learning first. The fancier redstone layouts can behave differently between editions — piston timing and TNT duping in particular are Java specialties — so if you graduate to an advanced design, check that it was built for your edition before you pour the lava.

Practical Tips

• Build the frame from non-flammable blocks; wood anywhere near the lava flow is a fire waiting for a tick.
• A pickaxe with Efficiency makes the simple design feel twice as fast; add Haste from a beacon later and it outpaces most needs.
• Mine stone-textured variants with Silk Touch once you graduate to a stone generator design, if your build palette wants smooth stone blocks.