Smelter

Smelter is an unlockable activated item added in The Binding of Isaac: Afterbirth †.

Effects[ | ]

Upon use, any trinkets that Isaac is holding are destroyed, and their effects are permanently applied to him.
- Trinkets that are absorbed show up on the HUD's item tracker.
Increases the chance for a trinket to drop after clearing a room. (Has a 2% chance to turn the pickup variant into a trinket.)

While held, Mom's Box will double the effect of all absorbed trinkets (if their effects can be doubled).
Absorbing the Tick will allow Isaac to pick up other trinkets again.
Trinkets whose effects only activate once, such as Store Credit, Missing Poster, and Walnut, will still only activate once after being absorbed.
Perfection is still removed if Isaac takes damage from regular sources.
Faded Polaroid cannot be used to open A Strange Door if smelted.
It is possible to find previously smelted trinkets during a Victory Lap, or if the trinket Item Pool is exhausted.
Picking up a copy of a trinket which was already absorbed will not duplicate that trinket's effect.
The trinket will not be absorbed if Smelter is activated during the pickup animation.

Book of Virtues: Spawns yellow wisps on the middle ring. The wisps have a chance to spawn trinkets when destroyed.
Glyph of Balance: Allows a trinket to appear every time there's a room clear drop as long as the other room clear drop criteria aren't satisfied, as it empties the trinket slot.
Tainted Eden: Absorbed trinkets are not rerolled by Tainted Eden's passive effect.
Tainted Isaac: Absorbed trinkets do not take up an item slot.

Smelter alongside Marrow are currently the only items that can be unlocked specifically by defeating Mom's Heart or It Lives on hard mode playing as Apollyon.