How to dry PLA: low temperatures, short times, and safe methods

Short answer

Dry PLA at 40 to 50 C for 4 to 6 hours in a filament dryer or food dehydrator. PLA absorbs moisture more slowly than PETG, but a spool left open in a humid room still goes wet, and a wet spool pops, strings, and prints rough. The catch is that PLA softens low, around 55 to 60 C, so the heat has to stay under 50 C or the spool warps or fuses.

Why PLA needs care when drying

PLA is less hygroscopic than PETG or nylon, so it tolerates more open-air time, but it still goes wet in a humid room. The signs are the same as any filament: popping or hissing at the nozzle, a cloudy or rough surface, and fine strings between moves. Dry it, then store it sealed so you do not repeat the cycle.

The risk with PLA is the softening point. PLA softens around 55 to 60 C, so a dryer or oven that overshoots can fuse the filament to the spool or deform the spool itself. Hold the heat at 40 to 50 C and check the real temperature with a thermometer.

PLA drying methods

Keep it dry after

Drying PLA once is not the end. PLA re-absorbs moisture when it sits open, though more slowly than PETG, so store it sealed with desiccant. A small hygrometer in the bin tells you when the desiccant is spent and the spool is at risk.

For the material background, the PLA hub covers the filament, and the filament storage guide covers keeping a dry spool dry.