How to Clean the Stone in an Outdoor Pizza Oven

The procedure, in four steps

This is the method Ooni publish for their own baking stones, and it is dry from start to finish.

1. Burn it off. Run the oven at top temperature for 30 minutes. Ooni's regional guidance puts a number on it - 450 to 500 C, which is 850 to 900 F - and the residue turns to ash. Light residue, they note, will simply burn off during the preheat before your next cook, so most weeks there is nothing to do at all.

2. Let it cool. Their instruction is explicit: cool the oven before you brush or remove the stone. This is not only a burn risk. A hot stone is a stone under thermal stress, and brushing or lifting one is how you find out how brittle cordierite is.

3. Brush it dry. Sideways, back and forth, with a brush, then wipe with a dry cloth. The ash comes off; the stains do not, and are not meant to.

4. Flip it. If debris is still stuck after cooling, take the stone out, turn it over and put it back. The next fire "self-cleans" that face, in Ooni's own wording, and their product pages suggest flipping before the next use anyway to burn off excess flour. A square floor has two working faces and most owners only ever use one.

The two things that must never touch it

Water. Ooni's wording: "It is important that you do not apply any liquid directly to the stone or submerge the stone in water." Two separate failure modes sit behind that. Water on hot stone is a sudden temperature change, and sudden temperature changes crack stones - their page says exactly that, and the mechanism is in why pizza stones crack. Water in a cold stone is worse in a different way: a porous body holds it, and the next fire turns that trapped water into steam inside the stone.

Soap. "We do not recommend washing your pizza stone with soap or water." Unglazed cordierite absorbs detergent and gives it back, as flavor, for months. Dish soap is for the oven's outside, cleaned only when the oven is completely cool.

Why this is not the same job as cleaning a kitchen stone

The method on how to clean a pizza stone is written for a stone in a domestic oven that tops out around 550 F. That is enough to carbonize cheese over an hour, and it is the right approach for a kitchen.

An outdoor oven runs 300 to 400 degrees hotter and gets there in 15 to 20 minutes, which changes three things:

That third row is the practical one. Launching into a 900 F oven means loose flour and semolina under every base, and it scorches on contact - the trade-off is discussed in perforated vs solid pizza peel, because shedding that excess before launch is most of what a perforated peel is for. Black patches on a floor are mostly that, and they are harmless.

When the floor is finished rather than dirty

Ooni are clear that stains and discoloration are normal and are not a reason to replace anything - a sign of a well-used oven, in their words - as long as the surface is smooth. The only replacement trigger they publish is instability: a hairline crack may not affect performance, but a stone that no longer sits flat should be replaced.

We would add one more from the physics rather than from the maker. A floor that has separated into pieces, or that has a step across a crack, is a floor that will catch a peel and tear a base off it mid-launch. At that point it is a consumable, not a repair.

Replacement floors, and the fitment rule that governs them

This is the point at which cleaning turns into a purchase, so be precise about the one thing that decides it: a replacement floor has to match the cavity in all three dimensions, and no amount of material quality rescues a stone that does not fit. The model-by-model published numbers are in pizza stones for Ooni and portable ovens, including the honest assessment of third-party fitment claims. What follows is only the replacement decision.

Best for replacing a 12-inch oven floor cheaply: the ROCKSHEAT 13.2-inch square. Its listing publishes all three dimensions - 13.2 x 13.2 x 0.4 inches - and names the Ooni Koda 12, Fyra 12 and Uuni ovens, which is more fitment information than most third-party floors give you. Square, so it has two faces to flip between. The honest caveats: no published weight and no published heat rating, on a part that lives at 900 F, so the 5.3 lb figure on its card is ours, derived from the published dimensions - and third-party fitment is the stone maker's claim, not Ooni's.

Best for a Koda 16 owner who wants the maker's own part: the Ooni Koda 16 baking stone (and this is the fitment-certain option). Ooni publish its dimensions against their own cavity, which removes the fitment question entirely. It is the expensive way to solve this and the only way to be certain.

Best for keeping a spare on the shelf for a 13-inch cavity: the Ooni baking board. The standard 10 mm floor these ovens ship with, bought as a spare so a cracked stone does not cost you a weekend. Keeping the old one as the second face is the cheaper version of the same idea.

One thing not to do: move a kitchen stone into an outdoor oven. A 15 mm cordierite slab sized for an oven rack is the wrong dimensions, and a body that has spent a year absorbing oil at 500 F is not a body to introduce to 900 F. The Ooni guide above makes that case with the published numbers.