A condition where ceramics have been removed from the kiln before reaching their target temperature or soak time. Underfired clay remains porous, structurally weak, and prone to chipping. Underfired glazes typically look cloudy, dry, or rough because the silica has not fully melted into a glass.
Heard on the job
The bottom shelf was underfired, so the clear glaze came out looking like frosted glass.
Also heard as
- Underfiring
Related terms
Underfire
To fire a ceramic piece at a lower temperature or for less time than required for full maturation.
Firing
The process of heating ceramics or glass in a kiln to achieve a permanent chemical change.
Overfired
Describes a ceramic piece that has been subjected to excessive heat or prolonged firing.