Alchemy Factory Cauldron Recipes & How Cauldrons Work

What a cauldron actually does

The cauldron arrived at the demo-to-Early Access transition as the “Experimental Cauldron: can craft any three materials into an unknown new material.” Recipes are generated procedurally rather than hand-written, which is why the developers warned in May 2026 that a rebalance “may affect” existing recipes and why the June 2026 patch removed a hidden multiplier that had made some late-game outputs too easy.

In practice a cauldron sits on a heating device like any other consumer, with three input slots. The March 2026 guide this page leans on reduces it to four rules:

1. Map the input flow rates. Every slot needs its item arriving at least as fast as the cauldron consumes it, times the number of cauldrons in the stack.
2. Keep the ratios balanced. Do not change fertiliser, and do not raise Factory Efficiency without raising Logistics Efficiency, because nurseries ignore Factory Efficiency.
3. Control output flow. Never pull from a cauldron faster than it fills.
4. Test first. Save, build it in sandbox or off to the side, and only then feed the main line.

Inputs decide the product; nothing decides the rate but the product

The example the guide uses: the clay recipe from three red currant makes 16.7 clay a minute at 4.6 P/s of heat. The clay recipe from sage, sage powder and red currant makes exactly the same 16.7 a minute at 4.6 P/s. The second uses about half the fertiliser; the first cannot be broken because all three slots hold the same plant.

Three cauldrons of clay therefore need 50.1 per minute of each input. A nursery stack producing 60 of each is safe; a factory-efficiency skill point that lifts the cauldrons to 25 per minute is not, until belt speed and plant supply go up with it.

Recipes guides were using in Early Access

These worked in the builds they were recorded in (February to March 2026, v0.4.3 to v0.4.4). The June rebalance said early-game cauldron recipes like clay and coke were mostly unaffected and late-game ones like Star Dust were reworked; 1.0 changed the obsidian byproduct. Treat them as starting points to test, not guarantees.

Why players build cauldrons at all

The same guide’s demonstration: the traditional route to impure copper powder needs smelters, grinders for iron sand, soap and soap powder and an Athanor, and yields about five per minute. A cauldron fed flax, flax fibre and lavender yields roughly double. Cauldrons cost 20 Bronze Ingots (cut from 30 in March 2026), so the first cauldron recipe most guides recommend is impure copper powder, to make more cauldrons.

The other side of the community, represented in the guide’s own opening, prefers to build every product the traditional way at least once. There is no leaderboard; both are legitimate.

Item filters, and the cauldron achievements

Since April 2026 cauldrons have an item filter, added because “the chaos caused by accidentally messing it up was too punishing.” The two joke achievements are Overqualified (any cheap three-slot recipe that outputs a plank) and What are you doing? (place an Automatic Cashier in a catapult and fire it into a cauldron; nothing needs to be produced).

Sources: Uglarvisk, “Mastering the Cauldron Guide” (12 March 2026, transcript) and “How to Craft All 7 Relics” (9 February 2026, transcript); Demo-to-EA notes (11 December 2025); May Update Preview (15 May 2026); v0.5.4467 notes (2 June 2026); v0.4.4.4298 notes (15 April 2026); v0.4.3.4131 notes (6 March 2026); 1.0 Patch Notes.