Thursday, December 29, 2016

Asking a Legend a Question

Sure, the internet can be a horrible place. But sometimes it is amazing. I am astounded at the level of access to people it provides. I imagine that access can and regularly is abused. And then sometimes it isn't.

I had a weird question about gluten. I tried to find the answer online but couldn't. Then I wondered if I'd be able to ask an expert. The first person that came to mind was Harold McGee. He occasionally writes for the New York Times when food science comes up but more importantly, he basically wrote THE cooking science book. I bet you can't find a chef or culinary student that hasn't read it and kept On Food And Cooking around as a reference. Hell, even I have it.

So I sent Mr. McGee an email.

Hello Mr. McGee-
I have a odd question that combines science with food and since you literally wrote the book on that and were also foolish enough to leave a contact email address on your website, I'm bothering you with it.

Both my mother-in-law and sister-in-law have celiac disease and are on strict gluten free diets. I tend to be more careful than they are when preparing food. I have some pans, utensils and other kitchen tools that I keep strictly gluten free. There will be no cross contamination getting them sick on my watch. I am also a pizza freak in the process of building a wood fired oven. I have a little propane fueled pizza oven to play with until the brick oven is finished. My long term plan was to get the propane oven a new stone, clean everything thoroughly and make the propane oven gluten free so they could eat a decent gluten free pizza.

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.

I hope you are enjoying the holiday season and have a very happy 2017.

Thank you

I wasn't sure he'd get it. Of if he did get it, he's got to be a busy guy that doesn't have time to field questions from random people. He's Harold Freakin' McGee.

Just under 24 hours after I sent the email, I got this.

Hi Jon,
Thanks for your good wishes. 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.

A great 2017 to you as well--


How amazing is that? I thanked him and invited him over for pizza should he ever find himself in the area. I mentioned that I'm the pizza snob but I know beer and wine snobs so it will be a good time. I hope he takes me up on the offer. I’m assuming the beer and wine snobs know who they are. I’m sure they do.


  1. The internet is a wonderful, entertaining, useful and awful animal but when it works on that one off chance whim, it's amazing!

    I don't know much about the effects charring would have on gluten flour but I have to say I thought exactly what Mr. McGee said about the interior flour acting as insulation. I would think you would have to actually bake/char it so much it would be unedible.

    I know this is a very late response so you may have already found your answer. If you have, I'd be interested in the results as I have family members who have to be gluten free as well.

    Bake on my friend!

    1. So far, I've only cooked in the oven a few times. Each time the area I'd be cooking the gluten free pizza has been directly under the fire during the preheat. When I move the fire and take a floor temperature with a temperature gun it is around 750 degrees. My guess is that it has been at that temperature for over an hour. My feeling is that anything gluten is ash and the bigger risk lies in cross contamination in my kitchen. Little poofs of flour go everywhere when I make dough. I feel bad every time I see some airborne flour.

      All that being said, I think I'm too chicken to risk getting one of them sick and will probably go the separate oven route. Or maybe I can track down some kind of silicone pad that can take the heat to be safer.

      Planning to fire the oven up this weekend. Still learning how to drive it. Sunday will be the biggest pizza eating crowd since I started building the dome.