Pizza stone smoking or turned black

Why stones turn black

Every bake leaves a little behind: a trace of oil from the dough, a drip of cheese or sauce, flour that browns. Over weeks, this builds a dark patina. Most cooks see it as a sign of a well used stone, and it does not change the way the stone heats or bakes.

Black patches that are smooth and dry are fine. A sticky, shiny or greasy layer is not: that is fat that has not fully burned off, and it will smoke.

Why stones smoke

Smoke comes from organic matter burning. The usual culprits are oil brushed onto the stone in an attempt to season it, fat from meat or cheese, loose flour or semolina that burns at high heat, and food residue from cooking things other than pizza on it.

In a home oven at 250°C, residue smokes slowly and can set off the alarm. In an outdoor pizza oven at 400°C or more, it usually burns off quickly as a short puff of smoke.

How to stop the smoking

Let the stone cool fully. Scrape any lumps away with a plastic scraper or a stiff brush. Do not use soap, as the porous stone absorbs it. Then heat it hot, for 15 to 30 minutes with good ventilation, to burn off what is left. In an outdoor oven, run it at full heat and flip the stone if the maker allows it, so the dirty side faces the flame.

In a kitchen oven, open a window, turn on the extractor and run the oven at its highest setting. Some smoke is normal the first time; it should be much less on the next preheat.

1. 1

   Let the stone cool completely.

2. 2

   Scrape off lumps and brush away loose flour.

3. 3

   Wipe with a barely damp cloth if needed; do not soak.

4. 4

   Let it dry fully, ideally overnight.

5. 5

   Heat it hot for 15 to 30 minutes with good ventilation.

6. 6

   Brush off any ash once cool.

Note:Never put a hot stone in water or run water onto it. The sudden temperature change can crack it. Use oven gloves rated for high heat.

Do not oil a pizza stone

Unlike cast iron, cordierite stones do not need seasoning, and oil is the most common cause of smoking. The oil soaks into the pores and turns tacky, then smokes every time the stone is heated. Our do you need to season a pizza stone article explains more.

If you have oiled your stone, repeated hot burn-offs will clear most of it over time. Expect some smoke and staining along the way.

Keep it cleaner

Use a light dusting of semolina or rice flour rather than heaps of plain flour, which burns. Keep toppings away from the edge so they do not drip onto the stone. Bake things like roast vegetables or garlic bread in a tray rather than directly on the stone. Our how to clean a pizza stone guide covers routine care.

If smoke keeps returning in a kitchen oven, consider a dedicated outdoor oven, where high heat burns residue off in minutes. See best outdoor pizza ovens or, for indoors, best electric pizza ovens.

When a stone needs replacing

Replace a stone that has cracked right through, has deep chips that catch the peel or has absorbed so much oil that it smokes heavily despite repeated burn-offs. A hairline crack that has not opened can often still be used if it sits flat; see why did my pizza stone crack.

A darkened stone with no cracks is not worn out. It may well bake better than when it was new.

Frequently asked questions

Is a black pizza stone safe to use? A darkened stone from normal use is fine. Scrape off loose deposits and burn off any oil that smokes.

Can you wash a pizza stone with soap? No. The porous stone absorbs soap, which can taint later pizzas. Scrape and burn off instead.

Why does my pizza stone smell? Usually fat or cheese burning off. A hot burn-off with ventilation clears it.

Can I use oven cleaner on a pizza stone? No. Chemical oven cleaners soak into the stone. Use heat and a scraper.