The Pizza Lab: We Test KettlePizza and Baking Steel's New Joint Pizza Oven
Back in April, I asked this question:
What if Andris Lagsdin, creator of the Baking Steel and Al Contarino, inventor of the KettlePizza were to get together to create a model based on their two products that works exactly like my set up straight out of the box?
Thanks to fate, the internet, two inventors who are extraordinarily receptive to feedback, and perhaps a little push on my part, we've made it happen. I'd like you to meet one of the early models of the new KettlePizza and Baking Steel joint pizza oven.
I've been talking up the awesomeness of both the Baking Steel and the KettlePizza for a while now. The former is a thick steel sheet that you use in place of a stone for making pizza in your oven. Its high conductivity and thermal mass make it the ideal surface to get the blistered, browned, crackling crust you deserve. The latter is an after-market insert that will convert your Weber kettle-style grill into a full-blown pizza oven.
While both are great on their own, if you combine the KettlePizza with the Baking Steel, you can create an inexpensive outdoor pizza oven that will heat up to real Neapolitan oven temperatures in a fraction of the time of a stone or brick oven, and allow you to cook pizzas in under four minutes per pie, creating crusts that are incredible crisp and light with large, poofy bubbles and plenty of those micro-blisters that define a truly great slice.
The idea is that by placing the baking steel on top of the KettlePizza, you create a large thermal mass that radiates heat downwards while also creating convection patterns that draw hot air over your pie, cooking your pizza rapidly from the top and the bottom simultaneously.
The new joint project features the KettlePizza Pro Kit, which has a tombstone-shaped stone underneath for easy pie launching and retrieval, and open sides and back to allow you to add coals or wood to the fire on the fly. The Baking Steel is a custom-cut, 3/16ths-inch number that nestles on top of the unit. It's already gone through a couple of iterations, but the current model has vents along the sides to allow you to grip it and lift up and down (though don't do this after it's been preheating!), along with a vent in the back for adding fresh coals.
I fired it up a couple afternoons in a row to check out how it worked, and tweak any possible improvements.
The first thing I noticed was that the hole in the back lets a large amount of hot air escape. Even with the lid of the kettle grill firmly in place, flames lick up the back wall and through that hole. Ideally, convection currents would pull those flames forward and over the pizza in order to heat the steel efficiently.
Still, I managed to crank the sucker up to an air temperature of around 800°F with a floor and ceiling temperature of 700°F by using 12 1/2 pounds of charcoal and a couple of large oak logs.
Due to the lack of internal convection current, I had to dome the pies—that is, use the peel to lift them towards the roof of the oven for stronger radiant heat—for a significant portion of the baking time in order to brown the tops properly. But when those pies came out, man were they good. Check out this browning on this sausage and radicchio pie (one of my new favorite combos, incidentally):
And as expected, the leopard spotting on the undercarriage from a 700°F stone was sublime.
I've been in close contact with Al Contarino, the Kettle Pizza inventor ever since I tested the first model, making suggestions for upgrades based on my own experience and experiences reported to me from Slice'rs like you. We chatted a bit about the new kit and his first question to me was, "Do you think the back vent is necessary?"
While it's useful to have there for allowing you to drop in coals without inserting them through the mouth of the oven, for me, the loss of heat and convection inside the unit is a deal breaker—I'd take performance over convenience any day.
To test out whether a closed-back model would fare better, I fired up the grill again the next day, this time placing the Baking Steel insert in the unit reversed, so that the back was a solid steel sheet. I also covered the hole in the front with an extra piece of 3/16ths-inch steel.
After preheating with another 12 1/2 pounds of coal and two big oak logs for an hour, I'm happy to report that we buried the needle on the temperature gauge. I didn't have the IR thermometer the second day, but based on how fast pizzas browned and cooked, I'd estimate floor temps of around 750°F, air temps of close to 1000°F, and a ceiling temp of 800 to 900°F.
What's more, the flames now licked up the back of the oven and curled over the pizzas, helping them to puff and char in record time. Pies popped out of the oven regularly in under 4 minutes, and due to the high thermal mass of the stone and the steel, it required very few re-fueling pauses to maintain good pizza-firing temperatures.
Check out the oven spring on this crust. Nice airy bubbles!:
Here are a few pies we made (recipes coming later this week!):
Classic Margherita: buffalo mozzarella, San Marzano tomatoes, basil, extra-virgin olive oil and a sprinkle of Parm:
Mozzarella, goat's milk feta, figs, and basil:
Cherry tomatoes, fior di latte, garlic, basil, extra-virgin olive oil:
New York-Neapolitan: San Marzano tomatoes, Parm, basil, extra-virgin olive oil, and dry aged mozzarella.
After the pizzas were fired off, I noticed that the grill was still holding at a steady 600°F—a great temperature for roasting a spatchcocked chicken. It was a tight squeeze getting a chicken through the pizza oven door on a tray, but the results were worth it. Half an hour later we had roast chicken with crazy juicy meat and great crisp skin, all with a tinge of smoke from the oak fire.
And the fun didn't stop there! Turns out that the thick steel sheet also makes an excellent outdoor griddle. I get complaints all the time from folks who like making my smashed burgers, but don't enjoy the smoke that comes with it. Cooking on a coal-heated steel sheet is the answer to your prayers. It not only solves the smoke issues, but it also gets far hotter than you can heat a skillet on the stovetop, resulting in better searing and more efficient browning.
Sounds awesome, right? So here's the thing: there are currently no units available, and as Al and Andris have said, they've been making incremental improvements with each new redesign. That said, once the newest version with the closed back and the side handles comes out (and it should be within the next month or two), we may have finally achieved that holy grail of pizza-baking technology: an inexpensive pizza oven that works straight out of the box with no modifications, hacking, or hardcore manual labor necessary.
I predict a lot of happy backyard pizzaioli this holiday season.
The new combo kit is still in the works, but should be out soon. We'll keep you updated. In the meantime, if you're interested in either product on their own (both are highly recommended!), you can order the Baking Steel here ($79), or the KettlePizza here ($299.95 for full KettlePizza Pro Kit, which includes Tombstone ProGrate, and an aluminum pizza peel).
About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.