Slag — Officially Called Residue Now
Quick answer: the material you know as "slag" is officially called Residue in the current game. It comes off your Shakers, burns into Burnt Residue at roughly 4:1, and presses into guaranteed Gold — here is the whole pipeline, plus the rename history.
Material Data (Current)
| Field | Residue | Burnt Residue |
|---|---|---|
| Matter type / Density | Slushy / 50 | Solid / 50 |
| Obtained from | Wet Sand (on a Shaker) | Residue (burned) |
| Processed by | Fire | Kinetic Press |
| Byproducts | Burnt Residue | Gold, Seed |
| Burnable / Wettable / Launchable | Yes / No / Yes | No / No / Yes |
Where Residue Comes From
"Residue is produced by dropping Wet Sand on a Shaker." Every Wet Sand pixel becomes Residue; the Shaker's Gold output (25% chance) is the side prize — Residue is the guaranteed product, and it is not waste.
Burning: 25% Per Pixel, ~4:1 Overall
The conversion is lossy by design: "When Residue combines with Fire each pixel has a chance to either turn into Burnt Residue or be consumed with no output." The odds: "A Residue only has a 25% chance of turning into Burnt Residue" — which the wiki also states as "approximately 4 Residue → 1 Burnt Residue."
Ignition options: the Flamethrower or the Rocket Launcher's napalm upgrade manually; a Pyro Dispenser or lava trapped in Filters for automation. Helpfully, "with enough Residue input, a pile ignited by the player can burn continuously to keep producing Burnt Residue without having to keep reigniting."
Pressing: The Guaranteed Payoff
Burnt Residue is Kinetic Press food: "By dropping Burnt Residue onto a Kinetic Press from 25+ blocks high, the Burnt Residue will be transformed into 1 Gold and 1 Seed." No randomness — "1 Burnt Residue will always output 1 Gold and 1 Seed."
Watch the drop height: pixels arriving from under 25 blocks just rest on the press and block it. The official fix is a row of angled Launchers along the top to fling stagnant pixels aside.
The Name History: Slag → Residue
In the 2025 demo era the chain was named Slag / Burnt Slag / Kinetic Slag Press, and the 2025 wiki described Shaker output as "Gold (↓) and Slag" with a 20–25% gold range. Old guides and forum posts still use those names.
The current game and wiki renamed everything: Residue / Burnt Residue / Kinetic Press, with the gold odds now stated as an exact 25%. The press byproduct changed too — 2025's Gold + Spore became today's Gold + Seed. Same chain, new vocabulary.
Budget for the burn loss
Plan quantities backwards: every Burnt Residue you want costs about 4 Residue, which costs about 4 Wet Sand. If your press tower runs dry, the bottleneck is almost always the burning stage — not the Shakers.
Slag Burner Setups
Automate the burning stage two ways.
Kinetic Press Guide
The 25-block drop, in detail.