Make and load a kiln
Make a kiln from eight cobble in a 3×3 ring with an empty center. Place it and right-click to open it. The left slot is input, the middle is fuel, and the right is output.
A valid process takes eight simulated seconds per item while burning fuel is available. Put in several inputs and enough fuel for repeat processing. The output slot must be empty or contain the same output item, and must have room in its stack.
| Input | Output |
|---|---|
| Copper ore | Copper ingot |
| Iron ore | Iron ingot |
| Titanium ore | Titanium ingot |
| Gold ore | Gold ingot |
| Iron ingot, with carbon-bearing fuel | Steel ingot |
| Sand | Glass |
| Cobble | Stone |
| Oak, birch or pine log | Charcoal |
| Raw pork, beef, goat, rabbit, venison, poultry or mutton | Matching cooked meat |
| Raw salmon or trout | Matching cooked fish |
| Raw crab | Cooked crab |
| Raw reef fish | Cooked reef fish |
| Hen egg | Cooked egg |
| Potato | Baked potato |
| Bread dough | Bread |
| Wet sponge | Sponge |
Some recipes also make bread directly in the grid. The kiln supports bread dough as a separate input.
How long fuel burns
| Fuel | Burn time per piece |
|---|---|
| Coal | 96 seconds |
| Charcoal | 40 seconds |
| Carbon | 16 seconds |
| Tree resin | 16 seconds |
| Oak, birch or pine log | 12 seconds |
| Firewood | 8 seconds |
| Oak or pine planks | 6 seconds |
| Sticks | 2 seconds |
Fuel choices are explicit. A newly added wood type is not automatically accepted as fuel; use one of the known fuels above. The kiln's current fuel and remaining burning reserve are saved.
Make steel
Place iron ingots in the input and use coal, charcoal or carbon in the fuel slot. If a suitable carbon-bearing reserve is already burning, it counts. Wood and resin do not satisfy the steel condition even when they can heat ordinary processes.
Troubleshooting
Nothing happens: check the input has a supported output and there is valid fuel. A kiln is not a general-purpose grid or chemistry bench.
Steel will not form: the input must be iron ingots, not iron ore, and the burning fuel must be coal, charcoal or carbon.
It stops partway: add fuel and check the output is not full or blocked by another item. Losing heat makes ordinary partial progress cool down; an invalid process or incompatible output resets progress.
Waiting for a process: kilns advance with simulation time and continue while ordinary menus are open. Saving and returning to the title or closing the game stops active world processing. Known kilns are processed while the world is open; do not rely on walking away to stop a burn. The current /freeze_all command does not freeze the world.