Direct answer

The Cauldron transforms items: official achievements prove Plank → Oblivion Essence, Vitality Essence → Oblivion Essence, plank production in the Cauldron and wood produced by Cauldron. It is unlocked through Cauldron research (Steam: “Traditional Alchemy”). Other combinations are community leads until reproduced on the current build.

Community sites describe the Cauldron as a “formula” machine with multiple input slots, heat management and stable-feed behavior. That model matches the achievements and the game’s own description of magical devices. The mechanics guide How the Cauldron works covers feeding and heat; this page is the formula table.

Verified formulas (official evidence)

Plank → Oblivion Essence

Input: 1× Plank  →  Output: Oblivion Essence
Evidence: Steam achievement “Tenacity” — Craft a Plank into an Oblivion Essence.

Vitality Essence → Oblivion Essence

Input: Vitality Essence  →  Output: Oblivion Essence
Evidence: Steam achievement “Vitae & Mors” — Craft a Vitality Essence into an Oblivion Essence.

Inputs → Plank

Output: Plank (produced inside the Cauldron)
Evidence: Steam achievement “Overqualified” — Produce a plank with a cauldron.

Inputs → Wood

Output: Wood (Cauldron production)
Evidence: Steam global achievement “Wood by Cauldron” (2.2% of players).

What the formula table will hold

While each combination is re-verified, the reference table below covers the confirmed cells. Every unlocked cell is linked to its item and machine page.

Input AInput BOutputStatus
PlankOblivion EssenceOFFICIAL
Vitality EssenceOblivion EssenceOFFICIAL
VariousPlankOFFICIAL
VariousWoodOFFICIAL
Sulfur + …?COMMUNITY
Other community combos?PENDING
Cauldron data must not be forced into one-recipe-per-item thinking

Community evidence suggests alternative combinations, extra input slots and behavior that depends on heat and stable feeding. Until reproduced on the current build, community explanations of the Cauldron algorithm are research leads only.

Highest-value targets

Players search most for “best cauldron recipes” — the decision guide is on Best Cauldron recipes. Short answer: prioritize formulas whose outputs feed Philosopher’s Stone progress or unlock sell value, but wait for the verified table before optimizing around exact quantities.

Bug-adjacent fun fact

The Steam achievement “What are you doing?” requires throwing an Automatic Cashier into a Cauldron with a Catapult — the Cauldron accepts more than raw materials.

Independent fan reference for Alchemy Factory. Game data refers to the current official 1.0 build (Steam, PC). Field-level evidence is flagged on each page with OFFICIAL / OBSERVED / COMMUNITY badges; amounts shown without a badge come from the official 1.0 patch notes or store descriptions.