Man Builds Coal-Oven Grill Simulator


Editor's note: A short time ago, homeslice Philip G. got in touch, telling me there was a post on that was making quite a stir: Reverse-Engineered Coal-Fired Brick Oven. Apparently, a Michigan man had invented a grill insert that he claimed simulated a coal- or wood-fired oven. I clicked over and became fascinated by the metal-and-stone device (pictured below). Could something so simple-looking achieve the holy grail of at-home pizza-makinghot enough and consistent enough temperatures to perfectly cook a pie? I don't know yet, because my 2stone Pizza Grill has only today begun its UPS journey to my home in Brooklyn. Anyway, Philip has been in on the 2stone discussion thread on since the beginning, so he offered to do a Q &A with the inventor, Willard Gustavsen. Here 'tis. Many thanks to Philip! Adam


Name: Willard Gustavsen
Location: Southwest Michigan
Occupation: Designer, manufacturer, builder

Tell us a little bit about where this project came fromwhere did you initially get the idea to make a pizza-oven insert for grills?

Most of the design work I have done has been related to specialty tools for the building industry. I have either sold the patent rights or have manufactured products and private-labeled them for companies. I have always liked good pizza and thought it would be a fun project; to see if I could design a simple oven or tool that could duplicate the results of an authentic wood-fired hearth oven. Essentially the 2stone Pizza Grill is just another tool of sorts.

At first, all of my prototypes were wood-burning and were a combination of steel and fire bricks. I tried many different styles, mostly looking for a way to reduce the number of bricks it took and also trying to find ways to shorten the fire-up time. Since I genuinely like pizza and pizza-making, it was more interesting than some of the other projects I've worked on. I kind of had my doubts about making something saleable, because it could be really expensive to ship a lot of bricks around the country.

I guess that's where I started thinking about a grill insert. I already had a grill "the heat source" and I figured most people do, so why bother reinventing "the heat part"? I also got tired of having to burn all that slab wood just for two pizzas.

How long has it taken to get all the kinks out of the system, from start to finish?

I started 5 or 6 years ago. I didn't work on it all the time but kept thinking about it in the back of my mind. I would scrap the last prototype and build a new one, always looking for a way to do more with lessfewer firebricks and shorter fire-up times, for example. Once the final concept was down, it did boil down to ironing out the kinks, as you say.

Photographs courtesy

Watching your video, I noticed that the rotating design seemed super effective. Was that in the original plan or is that something that was added afterward?

No. I did not have "rotating hearth" in the original prototype. That is where the diamond plate came into the picture, as a place to quickly put the pizza and turn it around. A large concentration of the heat is coming from the back, so of course it had to be turned. So it only made sense not to interrupt the baking process while the pizza was being rotated. It also provided a means to evenly heat the baking stone.

We all know that most of the top-notch pizzerias use ovens that reach very hot temperatures. Obviously your grill insert is designed to replicate that. What is the temperature consumers could expect to reach using the device?

In my testing, I bought two uncooked pizzas from the local Italian pizzeria. I baked one in the home oven and the other in a high-heat hearth oven. I was completely amazed by the difference the high heat made.

650°F to 700°F seems to be what I am able to get from my gas grill. On charcoal (if you really load it up) I think it can get too hot. Charcoal has more of a learning curve, since there are many variables to consider. The high heat was one of the reasons I worked to achieve an open-door design. By having the door open all the time, it became a lot easier to produce a perfect bake. Fifteen seconds can make the difference when it's really hot. The draft also simulates a wood-fired hearth oven and is the reason you can have an open-door design.

The big question: When will it be available and how much?

We are in production now and will start shipping within a few days. So far the response has been great, and we have taken quite a few orders. The Price is $257.65, plus shipping. It is available at Our online store, which also includes some accessories, will be open soon.

Anything else you'd like to say to all the budding pizza-makers and pizza fans out there?

If you have been bitten by the pizza bug, you are not alone. Join a good forum, and you can learn from other enthusiasts and contribute some of your own tricks that you'll learn along the way. Pizza-making is a lot of fun and intricate enough that you will never stop learning. Between the crust, sauce, cheese, toppings, and baking, there is more to it than meets the eye. The best of luck to you, in your quest for that "Elusive Pie."