Using a portable wood fired oven for glutenfree baking

[Sandurz]

Hello everybody.

I have an Ooni Karu wood fired portable oven and a Celiac relative.

I was wondering what kind of decontamination should the oven and stone undergo before cooking a safe gluten free pizza.

Is running it at high temperatures (400-500 °C) for a given period of time enough to destroy any gluten residues?

[Jon in Albany]

I once sent an email to food scientist Harold McGee asking something similar. I have a wood oven and wanted to know if I could safely bake a gluten free pizza in there before cooking wheat based pizzas. My thought was that the oven heating process would turn any residual flour into ash. Here's the question part of what I wrote:

So here's my question: at what temperature would high gluten pizza flour burn up and no longer contain gluten? The oven would be heated up to a minimum of 600 degrees F and often hotter depending on the style of pizza I'm making. My thought is that if I fired the wood oven hot enough and long enough, any residual flour on the oven floor would become gluten free ash. If I cooked a few gluten free pizzas before making traditional pizzas using a separate, gluten free pizza peel they could enjoy a wood fired pizza too. If you think the risk of cross contamination would still be present, I'll move ahead with just the separate, gluten free propane pizza oven plan. It pains me to see the frozen gluten free pizza they eat at parties. I'd like to change that this summer.

And here's his answer:

About gluten: it does seem reasonable that temperatures high enough to char flour would completely eliminate the immunological reactivity of gluten. But I've been unable to find any studies that have actually demonstrated it. And I suppose it's remotely possible that some flour aggregates could char on the outside while insulating the interior. If you go ahead with one oven, I would just be sure to give it plenty of time to mineralize any residues from the last batch.

I took that as there were no guarantees the gluten would be completely gone. So what I did was buy a Blackstone on closeout and I keep it gluten free. My concern was that something would get in between the bricks on the floor and somehow cross contaminate the gluten free pizza. The celiacs I know aren't getting sick on my watch. It might be different in an Ooni. Never cooked in one but I think the floor is a solid piece.

[Pizza_Not_War]

With no scientific proof I'd suggest that a person afflicted with Celiac would more likely pick up Gluten from almost any other source of food, cosmetics, toothpaste, etc. than a high temperature pizza oven.

[Sandurz]

My guess is that if you get the oven above 400°C there will be no problem, but of course I can't be sure either.
The advantage of the Ooni oven could be that given its low heat inertia one could easily bring it up to that temperature and it will cool down quickly if the desired style of pizza requires it.

On a related note, here in Italy there is something called "grano arso - burnt wheat" which is the wheat that has been left after the fileld has been harvested and the tow has been burned.
Poor people then went to the fields to get what was left of the seeds to have something to eat, much later this caught the attention of chefs that started experimenting with it.

It is known that the gluten in that kind of wheat is compromised, but again there are no studies and is not considered safe for celiac patients.
(of course the grains in this case are somewhat intact and it's very different from the flour burnt in the oven).

[Jon in Albany]

There are plenty of other places besides the oven floor to cross contaminate. I may be a little over the top, but I have some pots, bowls, a pizza sceen, pizza pan and pizza cutter that I keep gluten free.

I've seen cross contamination ruin a day or two for someone. The two main celiacs I cook for are my mother in law and sister in law. Don't want them getting ill on my watch.

[Sandurz]

Yeah but the other places I have full control on.
My mother has known to be Celiac since the early 80s, I know how to avoid that kind of stuff.

[Zinc]

Fwiw, I have celiac, and have had cross contamination from a wood fired oven several times before. I am very sensitive to cross contamination though, but it is something to consider if the celiac you will be cooking for is also very sensitive. Perhaps make her a pan/deep dish in the oven instead?

[Sandurz]

Thanks for sharing your experience @Zinc.

Do you think that using a different gluten-free only pizza stone on top of the oven pizza stone could solve the problem?

I could then remove it too keep it GF (yeah handling a 400°C pizza stone is not the most sane thing you can think of but...)

[Zinc]

It might work ok, as long as the oven interior is cleaned out well, and if you launch the gf pie first. The reason being, is that flour can stay airborne for a while, and still make someone sick.

https://nationalceliac.org/celiac-disease-questions/airborne-gluten/

I helped a local cookie company out in the past with trying to develop a good GF cookie, and I got pretty sick after touring the production area, so it is definitely a big concern if you are sensitive to cross contamination like myself.

I know this isn't the definitive answer you were probably hoping for, but hopefully it helps.

[Sandurz]

The process I had in mind was:

Put the pizza stone with the flat part (the one without the debossed logo) facing up.
Fire the oven and bring it up to 4-500 °c for some time 15-20 minutes?
Bring out (I prepare and bake the pizzas outside) all the tools properly cleaned and all the gluten free ingredients.
Prepare the GF pizzas bake and serve them.
Bring out all the non GF ingredients and proceed to pizza making as usual.

[Zinc]

It sounds like it might be alright as long you clean any loose flour or charred bits that are in the oven first, since high heat does not break down gluten to the point that it would not trigger a reaction. If it were me though, I would not have the original stone in the oven under the 'gluten free' stone. I would also make sure to do an extremely thorough cleaning before hand on the oven interior.

If money permits, and you see yourself making gluten free pies often for the person you're talking about, it might just be easier to invest in a cheaper second oven to have on hand for those occasions.

Good luck.