If “cinder” means burnt slag, follow the checked heat-to-press route.

Direct answer

Cinder is not an established synonym in the captured sources; the closest documented term is Burnt Slag.

The captured publisher-wiki result names Burnt Slag as the material handled by the Kinetic Slag Press. It does not equate “cinder” with Burnt Slag, so first confirm the exact in-game label and do not route an unknown material by name alone.

Inferred term mapping · useful for the query, not a verified synonym.

Processing role

When the current build confirms the burnt-slag interpretation, use the reported heat-to-press sequence.

1. Run a small slag batch over lava contained in a filter; the Steam discussion reports this cooks slag automatically.
2. Keep unprocessed material separate and make any recirculation path observable before scaling.
3. Route only the checked Burnt Slag toward the Kinetic Slag Press, the inferred source's documented next processing stage.
4. If the current build uses a different label or the output does not match, stop and re-identify the material rather than substituting cinder, slag, or burnt slag.

Community heat setup + Inferred press role · no universal ratio or recipe is claimed.

Community reports

The useful player guidance is about heat and flow control—not a cinder recipe.

The Steam slag discussion reports lava inside a filter with slag passing over the top, plus an optional end filter to recirculate uncooked slag. A separate filter discussion reports that mixed slag and burnt slag can clog a line and recommends thinner flow and lifts as troubleshooting ideas. These are community reports; they explain how to investigate the nearby chain, not how to guarantee a cinder output.

Scope

Keep the cinder label, burnt-slag route, and exact recipe separate.

No captured page identifies an official cinder item or a cinder-specific recipe. This page's processing answer is conditional: if the current build uses cinder as an alias for Burnt Slag, start with the source-checked heat-to-press route; otherwise identify the material first. No exact ratio, unlock cost, or guaranteed output is published.