Troubleshooting · symptom → cause → fix
My pizza stone cracked
The pizza stone has cracked – or broken in two – in the oven.
Most likely cause
Thermal shock
How you know: The stone went into an already hot oven, or something cold or wet landed on it while it was hot.
Do this: Always put the stone in a cold oven and heat them up together. Let it cool down in the oven afterwards.
Other possible causes
-
Moisture in the stone
- How to tell
- The stone has been washed, soaked or stored somewhere damp.
- Fix
- Never wash the stone with water. Scrape and brush it dry. If it has got wet: let it dry for several days before heating it.
-
Uneven heat
- How to tell
- The stone sits directly on the oven floor or very close to an element.
- Fix
- Put the stone on a rack, not directly against the heating element.
-
The material can't take the heat
- How to tell
- Thin ceramic or a cheap stone not made for high temperatures.
- Fix
- Choose cordierite, or switch to steel, which can't crack.
Quick answer: almost always thermal shock – the stone is heated or cooled too quickly and unevenly – or moisture that expands into steam inside the material. Heat the stone from a cold oven and keep it dry.
The nerdy explanation
Ceramic materials handle high heat well but cope badly with rapid temperature changes. When one part of the stone gets much hotter than the rest, stresses build up, and water absorbed into the pores turns to steam and can crack the stone from the inside. Steel doesn’t have that problem – one reason many people switch to steel for the home oven.
See pizza stone and baking steel. More problems are in the troubleshooting section.
Frequently asked questions
Can I keep using a cracked stone?
A hairline crack may hold for a while, but the stone can break under a pizza. If it's in two pieces, the halves can often be used together until you buy a new one, as long as they sit steady.
Why is my stone stained?
Stains and discolouration are normal and don't affect how it works. Only cracks are a problem.