Alchemy Factory Best Fuel: Tiers & Coke Powder
Quick answer
The best practical mid-game fuel in Alchemy Factory is coke powder made from coal ore in a stone crusher. It gives the highest heat-per-item among easy-to-produce fuels, runs a self-fuelling loop on just three stone crushers, and avoids the massive machine footprint of the Athanor route.
How fuel actually works
Heat is measured in P per second. A heating device (furnace) burns fuel to make heat, and every consumer stacked on it draws a fixed amount — a crucible always takes 4 P/s no matter what it processes. The fuel you choose changes only how long the furnace runs before it needs the next item; it never changes how fast the machines work.
Version 1.0 removed the base heat cost that heating devices used to draw on their own, so an idle furnace no longer slowly eats its own stack. When sizing a furnace, you simply add up the consumers on it.
The three fuel tiers
Fuels climb in three tiers. Raw fuels — logs, planks, and coal ore — can be burned directly but are really meant for refining. Player figures from the Steam community put a 200-copper log at about 22 heat per plank and a 4,800-copper coal ore at about 594 heat per coal.
Refined fuels — charcoal, coal, and coke — multiply the heat of their raw source; guides agree refining is almost always worth it. Powders and potions — charcoal powder, coke powder, black powder, blast potion, and panacea potion — deliver the highest heat per item.
Why coke powder wins the mid-game
The practical ladder most players climb goes: planks in the tutorial, charcoal around tier 5, then coal and coke powder at tier 6 once coal ore unlocks, black powder from a cauldron in the mid-game, then blast potions and finally panacea potions, which are fuel and fertiliser at once.
Coke powder specifically is the cheapest reliable mid-game fuel. The coal-ore route runs coal ore through a stone crusher for 120 coal, then 1 coal to 1 coke powder, using three stone crushers. The setup burns only about 3 coke powder per minute and nets about 57 — a fraction of the footprint with no fertiliser conflict.
The Athanor alternative (and why not)
The Athanor route converts 12 charcoal powder into 1 coke powder using six Athanors, 40 crucibles, and 60 grinders. It cuts material cost roughly in half but needs about ten times the machines and fuels itself, burning around 34 coke powder per minute.
New players often reach for it because coal ore costs 4,800 copper, but the comparison argues the other way: whatever you build or burn with coke powder sells for far more than the ore cost, and money scales with in-game days. The coal-ore route is the recommended default.
Black powder and panacea potion
Black powder is a high-heat fuel made in a cauldron in the mid-game; its heat value and sell price were both doubled in the June 2026 patch (v0.5.4467), so any older fuel comparison undervalues it. Panacea potion doubles as fertiliser, letting one belt feed both furnaces and nurseries on a floor.
What stays unconfirmed
Exact P values for the Kiln, Smelter, Alembic, Athanor, and Thermal Extractor were not listed in the source transcript, so their per-device heat draws are 待确认 — read each tooltip's P value and add them up per furnace. Late-game fuel strategy beyond panacea potions is also 待确认.