Coal is the fuel that keeps every smelter and blast furnace in Valheim running, and burning food on a cooking station will never keep up with demand. The reliable answer is the Charcoal Kiln, a stone structure that quietly converts logs into coal while you get on with other work.
Quick answer: Build a Charcoal Kiln with 20 Stone and 5 Surtling cores near a workbench, place it on bare ground, then interact with the front to load wood. Each piece of wood becomes one coal roughly every 16 seconds, up to 25 at a time.
Charcoal Kiln requirements: 20 Stone and 5 Surtling cores
The recipe itself is cheap. The gate is the Surtling cores, which come from the burial chamber dungeons scattered through the Black Forest. Picking up your first core is also what unlocks the kiln in the build menu, so there is nothing to research or discover beyond that.
| Requirement | Detail |
|---|---|
| Materials | Stone x20, Surtling core x5 |
| Crafting station | Workbench in range |
| Unlock | Pick up any Surtling core |
| Footprint | Roughly 4×4 |
| Placement | Terrain or stone structures only, not wooden floors |
| Rain | No damage; a roof is optional |
Because the kiln refuses wooden floors, most players sink it into flat ground just outside the base or set it on a stone platform. Terraforming with a hoe to bring dirt level with a wooden floor is the usual workaround if you want it indoors.
How to build the Charcoal Kiln
Loading wood and the coal output rate
Walk up to the front of the kiln with wood in your inventory and interact with it. Each press adds a single log, the message “Added Wood” appears, and the counter climbs toward its cap of 25. One piece of wood always yields exactly one coal.
Three wood types are accepted, and the kiln pulls from your inventory in a fixed order rather than asking you to choose. That order is Wood first, then Finewood, then Corewood, which is worth remembering if you are carrying birch or pine you meant to save for a longship.
| Property | Value |
|---|---|
| Conversion | 1 wood to 1 coal |
| Speed | 1 coal every 16 seconds |
| Capacity | 25 wood |
| Accepted fuel | Wood, Finewood, Corewood |
| Priority order | Wood, then Finewood, then Corewood |
| Coal stack size | 50 |
A full kiln takes a little over six minutes of real time to clear. Sleeping through the night speeds that along, since the kiln processes materials during the time skip the same way a smelter does. Cores are cheap enough that most bases end up with two or three kilns running side by side.
Note: If you later need those 20 stone and 5 cores for a smelter, destroying the kiln with a hammer returns every material used, so you can freely swap between the two.
Stop the coal from rolling away
Coal is a physics object once it leaves the kiln, and on sloped or bumpy terrain it scatters into the grass. Flatten the area first with a hoe using the Level Ground option, which fixes most of the problem on its own.
For a proper catch basin, ring the output side with Decorative Boulders. They cost 10 Stone each and act as a low wall that keeps every lump within arm’s reach, so you can scoop up a full batch in one pass instead of hunting for stragglers.
How to tell the kiln is working
The hover prompt reads “Charcoal Kiln (0/25)” and updates every time you add a log. Once you hit the cap it responds with “It’s full” and refuses further wood. An active kiln also glows and gives off the Fire effect, warming you and scaring off certain creatures within about two meters of it.
If nothing happens when you try to place it, the cause is almost always one of two things. Either there is no workbench covering the spot, or you are aiming at a wooden floor. Move onto bare ground inside the workbench circle and it will snap into place.
Other ways to get coal in Valheim
The kiln is the sustainable option, but coal shows up elsewhere too. Early on, before you have found any Surtling cores, deliberately overcooking meat on a cooking station is the only method available. It works, though it burns food you would rather eat.
| Source | Notes |
|---|---|
| Charcoal Kiln | Best rate; 1 coal per wood, repeatable |
| Overcooked meat | Any meat left on a cooking station; wasteful |
| Surtlings | Always drop coal; found at fire geysers in the Swamp and in the Ashlands |
| Chests | Occasional random loot |
| Obliterator | Converts items into coal, including bait bought with coins |
| Burning wood stacks | Igniting a placed Wood stack in the Ashlands yields 50 coal per pile |
How much coal you actually need
Smelting is where almost all of it goes. Copper, tin, iron, silver, black metal, and flametal all burn coal in a smelter or blast furnace, at roughly two coal for every bar of metal. A single trip’s worth of ore can easily eat a hundred logs.
Beyond fuel, coal is a build and craft material. Signs, forges, braziers, and banners all list it, as do the Cape of Odin, the Hood of Odin, the pointy hat, and poison resistance mead base. Coal also travels through portals, so a kiln farm at one base can supply a mining outpost somewhere else.
Set the kiln up once, keep a chest of spare logs beside it, and top it off whenever you pass by. It costs nothing to run and quietly removes the fuel bottleneck from the rest of the game.
