How to Hack Your Grill Into a Superior Pizza Oven

Update: Andris Lagsdin, fan of Modernist Cuisine and steel expert has just launched a Kickstarter for Baking Steel, a low-cost slab of pre-cut steel for baking pizzas and breads in just the way I describe below! I’ve tested one of his prototype units and it performs like a champ – even with a single Baking Steel (no double-decker) I was able to produce fantastic, wood-fired-oven-like results on my grill!  I highly recommend this Kickstarter for anyone looking to make pizza or breads at home.

The guys from Tested.com came to Seattle, so I shared with them one of the projects that’s been on my mind lately: making perfect pizzas at home.  In a previous post, I discussed my approach to making great pizza dough.  But, dough is only one half of the equation.  Without a good oven, the best dough in the world still won’t produce quality pizza.

Now, let me first say that there are people who devote their entire lives to pizza ovens – to building them, to studying them, and to understanding how they work.  I am not one of those people, and, although I still have a blank space in my yard that I one day hope to fill with an actual pizza oven, my goal here was to produce the best pizzas possible using my CharBroil infrared grill as a starting point.  But if you want to send me a pizza oven, I’ll test the shit out of it.

There are two keys to hacking a grill into an effective pizza oven: getting it really goddamned hot, and holding the heat.  Getting a grill hot is not so much of a challenge – add enough charcoal and let it burn for long enough, and you’ll have quite an inferno.  Add more airflow or additional oxygen, and your fire will burn hotter and faster.  But, retaining that high heat when you open the lid or add cold food… well, that requires mass.

Physics Interlude!

Mass, like a pizza stone, or the thick floor of a pizza oven, or in this case, 25-lb steel plates, act like a heat battery, storing up heat energy.  I was first turned on to the idea of using steel instead of ceramic brick by Modernist Cuisine, who recommend the technique not only for grills but for household ovens as well.  So, why are steel plates better than a pizza stone?  A few reasons:

  1. Steel is much denser than ceramic materials.  A typical pizza stone has a a density of 0.0625 lbs. per cubic inch.  The steel plates I’m using have a density of 0.329 lbs. per cubic inch – about 5 times as dense.  That means that for the same volume of material, I can store much more energy in steel than brick.
  2. Steel has a much lower specific heat than brick.  This means that it takes less energy to heat a steel block than a brick of equal mass.  So, the steel will heat up faster in the oven.
  3. Steel has a much higher thermal conductivity than brick.  Thermal conductivity measures how quickly heat moves through a material, or between materials via conduction. This means that the heat can move from the steel plate to the pizza crust faster than it could if I were using a ceramic material.

All of these factors are summed up in one convenient measure, known as thermal diffusivity.  And, it turns out that the thermal diffusivity of 304 steel (the grade I’m using) is about ten times greater than the thermal diffusivity of brick.  [I don’t have precise numbers for the ceramic composition of pizza stones specifically, but it will be similar in magnitude.  Some types of steel, like high-carbon steel, have more than 20 times the thermal diffusivity of brick.] 

Do ceramic pizza stones produce good-looking, great tasting pizzas?  Yes, absolutely.  But according to physics, they necessarily do so more slowly than steel.  One of my pizza criteria is a crunchy crust that will support its own weight when held from one end.  I’ve found great success in achieving this texture with a steel cooking surface.  The other advantage to steel, of course, is that it will last nearly forever.  I don’t have to worry about dropping and shattering it, I can use it as a griddle and scrape it clean, and if I need to build an impromptu blast shield, I’m all set.

To hack your grill into a worthy pizza oven, here’s what you’ll need:

To assemble your pizza oven:

  1. Place one of the stainless plates in a corner of your grill. 
  2. Place two of the stainless steel pipe segments on the two far corners of the plate.  Place the other two pipe segments on opposite edges of the plate, about 1/3 of the way back.  These pipe segments will hold up the top plate.  By pushing them back from the front corners, you allow yourself a little more room to negotiate the pizza with the peel.
  3. Place the top plate on top of the pipe segments.  It should sit firmly – you sure don’t want it crashing down on you during cooking.
  4. Install your BBQ grill fan or bellows on the opposite side of the grill, above the open grilling area not covered by the steel.
  5. If your grill has a charcoal tray or basin on the open side, fill it with charcoal.  If not, place the charcoal in a roasting pan or metal dish on that side of the grill.  Ignite the charcoal, turn on all of the burners and close the lid.  Allow the grill 45-60 minutes to preheat thoroughly. 
  6. A few minutes before cooking, start your grill fan or bellows.  This will boost the internal temperature of the grill and even out hot and cold spots.  A cooking temperature between 800°F and 900°F is ideal.
  7. Just before cooking, turn the burners below your steel plate down to 75% power.  This will help prevent the bottom crust from burning before the top crust is fully cooked.  However, I’ve found that the first pizza of the day is usually somewhat sacrificial 🙂
  8. Slide your pizza onto the bottom steel plate and cook, turning once, for 2-3 minutes or until the cheese is melted and the top crust is golden brown.  Keep the grill lid closed as much as possible during cooking to maintain the high temperature.
  9. Enjoy extraordinary pizza made at home!

I hope you enjoy the pleasure of homemade pizza as much as I have.  I’ve probably made 50 or so pizzas this summer, and there is nothing quite as satisfying than pulling a perfect pizza out of the grill and serving it to friends.  If you don’t (or can’t) have a grill, this technique works pretty well in a home oven, too.  Place one steel plate on the bottom floor of your oven to act as a heat battery.  Set the other on the top rack. Preheat your oven for an hour on its highest temperature setting.  You’ll need to add a minute or two to the baking time, but the results will be worth it!

No-Yeast, No-Rise, Champagne Pizza Dough

Update: Thanks to keen reader Edsel for pointing out that ModernistPantry.com is now selling WRISE.  This recipe was written for the standard version of WRISE, but they’ve recently introduced an aluminum-free version as well. 

I promised myself that, before the summer is over, I would learn to make fabulous pizza at home.  It turns out, making pizza at home is a fascinating problem.  Almost everyone I know eats pizza at home, but hardly anyone makes it… unless you count baking a frozen DiGiorno or putting toppings on a pre-baked crust.  My self-challenge encompasses aspects of both innovation and practice, and with a food as technique-centric as pizza, there’s no getting around the need to practice. I’ve made about 30 pizzas so far this summer, and my technique and confidence increases with each one.  However, I’ve recently made a breakthrough in recipe development that shows serious promise: no-yeast, no-rise, Champagne-flavored pizza dough that you can make from start to finish in under 40 minutes.  [pictured above]

Seriously. 40 minutes, from scratch. Minute 1: turning on the oven, taking out the stand mixer and grabbing a bag of flour.  Minute 40: eating a goddamn delightful pizza.

Champagne 2The secret to this recipe is microencapsulated leavener – a fine powder made of sodium bicarbonate (baking soda) and sodium aluminum phosphate that have been microscopically sheathed with non-trans palm lipid to prevent them from reacting with surrounding any acid until they are heated to the point at which the lipid coating melts away.  This means that the leavening action of the baking soda doesn’t kick in until the pizza is heated, and unlike yeast-based doughs, there’s no need for the dough to rise ahead of time.

I first read about encapsulated leaveners in Cesar Vega’s fantastic book, The Kitchen as Laboratory.  Tom Tongue, the R&D Director at Innovative Food Processors contributed a chapter that discusses the use of these products in commercial, take-and-bake pizzas.  I was immediately fascinated by the concept and tracked down a sample package of WRISE from The Wright Group.

In my first tests, I simply added a bit of WRISE to a traditional pizza dough recipe (actually, the Neapolitan pizza dough recipe from the upcoming Modernist Cuisine at Home, to which I have access, neener neener).  Although you’ll need to buy the book to read the full recipe, it relies on yeast and a rise time of at least one hour before baking.

DSC_7292

A few weeks ago, Cesar Vega and Alex Talbot (IdeasInFood.com) happened to be passing through Seattle and joined Jethro and me for dinner at my place. Among other things, we made pizza using the yeast + WRISE method, and I let the dough proof at 55°F for 6 hours before rolling out the crusts. The pizzas were great, but Alex was quick to plant a nagging question in the back of my mind: why do we need yeast in the dough if we have another source of leavening already? It was a great question, and one I couldn’t shake. The yeast and leavener combined to create an extraordinarily light and puffy pizza crust, which I loved, but presumably one could generate enough lift from the leavener alone. Of course, yeast adds flavor to the dough, but flavor can come from lots of sources other than yeast. Buttermilk, whey, blue cheese, soy, miso, beer, and a dozen other foods could stand in for yeast to produce an interesting dough. Then, Alex threw down another challenge: make a new batch of dough, and bake it without letting it rise to see just how much lift the encapsulated leavened provided.

So I did.  The dough recipe takes 20 minutes to make, which includes 10 minutes of rest time in between 5-minute kneading cycles in the stand mixer.  As soon as the second knead was done, I portioned the dough, stretched it into a 12-inch crust, and threw it in my 850°F grill-turned-pizza-oven (more on that later – it’s badass).  The dough rose, but not nearly as much as the yeast dough that had been left to rise for several hours.  A few bites into this “test” pizza, I realized that there was very little acid in the dough with which the sodium bicarbonate could react, which would explain the measly rise.  The only acid, in fact, came from a small amount of honey.  The liquid content of the dough was all water.  The next logical step was to replace the water with a flavorful, acidic liquid and see what happened.

Over the next few weeks, I went to work testing yeastless, WRISE-only dough variations.  Now, this is probably a good time to explain that I’m a shitty baker, and my scientific knowledge of the processes that take place inside wheat doughs is limited to some light reading on Wikipedia.  However, there’s nothing like empirical experimentation to help me learn my way around a concept, so I have no problem conducting experiments to which a wiser man may already know the outcome.

My experimental setup is as follows.  I preheated my oven to it’s highest setting (around 550°F, according to infrared thermometer readings) for one hour, with a 25-lb, 1/4” thick stainless steel plate set on the top rack.  As described in Modernist Cuisine and Modernist Cuisine at Home, a steel plate makes a fantastic pizza stone.  It has a greater thermal capacity than ceramic stones due to it’s higher density, and the higher coefficient of thermal conductivity means that heat can move out of the steel and into the crust faster than it can from a ceramic stone.  I divided each dough recipe into two 200-gram portions, and stretched them as thinly as I could while still maintaining their integrity (no holes).  I rolled, stretched, topped and baked one portion of the dough as soon as it came out of the mixer (left column in the image below).  I let the second portion rest for 15 minutes at room temperature to allow the gluten to relax (right column in the image below).  I topped each pizza with 15g of store-bough pizza sauce and 100g of shredded mozzarella cheese.  Nothin’ fancy here, just aiming for controlled conditions across my tests.  As a control for yeast-based dough, I used a bag of Trader Joe’s premade pizza dough, which calls for a 15-minute rest before using, as it comes refrigerated from the store.

crust results

My goal was to achieve a flavorful, well-risen dough by varying the liquid content across trials.  Besides the liquid, the recipe for each of the doughs was exactly the same.  I specifically chose acidic liquids so that the encapsulated baking soda would have something with which to react to produce the CO2 gas that fills good pizza dough with lovely pockets of emptiness.  Each of the pizzas took between 3 and 4 minutes to bake in my oven.  I ascribe the time differences to cycle timing of the broiler element in my oven – when the broiler is on, the pizza bakes much faster than when the broiler is clicked off.  Here are the results from my trials:

Trader Joe’s Premade Pizza Dough [Control]

[Pictured top-right]  This made a totally decent pizza crust.  It rose well, it was easy to stretch out into 12-inch rounds, and if you live less than 12.5 minutes from a Trader Joe’s, you can theoretically make pizza faster than with the from-scratch method below.  [12.5 minutes x 2 (round-trip) + 0 minute theoretical parking, shopping and checkout time, + 15 minute rest period = 40 minutes.]  Observe the relatively large number of big air pockets and the even rise around the crust.

Water

This trial, which you could also consider a control, I suppose, used 100% filtered water as the liquid content of the dough.  Much to my surprise, it rose pretty well!  As you can see in the recipe below, the only acid content is 4% honey, but the dough still lifted itself into a respectable pizza with a spongy texture and decent, though unremarkable, flavor.  I’m still a little shocked that the dough had this much lift from the acid in honey alone.

Champagne (er, Sparkling White…) – Winner!

In this trial I used a $5.99 sparkling white wine from Trader Joe’s as the liquid content of the dough.  I was counting on the acidity of the wine to react with the sodium bicarbonate, but naively hoping, as well, that the carbonation of the wine would add lift to the baked pizza.  It’s unclear that the carbonation did anything useful (all of the gas was likely released during the mixing process), but the “champagne dough” performed like a champ.  The flavors of the wine were easy to identify in the finished pizza, and the yeastiness you expect in dough was replaced by the similar yeastiness from the wine’s own fermentation.  I could detect apricot and cherry flavors in the pizza, even with the cheese and sauce present.  If topped with muscat grapes, and a wine-friendlier cheese than mozzarella, this could be a smashing success.  I’m excited by the variations that I can achieve using different sparkling (or non-sparkling) wines and more interesting topping combinations.

Buttermilk

I had high hopes for buttermilk.  Buttermilk is mildly acidic (pH around 4.5), but acidic enough that the encapsulated leavened readily foams if heated to 60C in the stuff.  Buttermilk is also delicious, with a wonderful sourness that I admire in pancakes and biscuits.  Unfortunately, [in this recipe, at least] it made very pathetic pizza dough.  Buttermilk must somehow interfere with the formation of the gluten network in the dough, preventing it from holding on to much of the expanding CO2 gas released by the leavener as the pizza bakes.  The dough was still quite tasty, but unfortunately didn’t meet the criteria I was looking for in terms of rise.  Bummer.

Bacardi Dark Rum

My line of thinking went like this: if Champagne worked, why not something even more acidic… like rum?!  As you can see in the image above (and as I found out later when researching this), alcohol interferes with gluten in dough.  I could tell just from the mixing process that this dough would suck – it was crumbly and inelastic, and too much stretching would cause it to tear easily.  But, I baked it anyway, and for my commitment, I was rewarded… it turns out that Bacardi pizza will self-flambe after 30 seconds or so of baking in a 550°F oven!  The pizza ignited in a poof of blue flame, then flames gently danced around the perimeter of the dough for the remainder of the baking time.  This pizza was giving off plenty of gas, as you can see by the pocket of lifted cheese in the 15-minute rest trial in the image above.  Unfortunately, the dough just couldn’t hold on and the pizza ended up basically unleavened.  The image below is a video frame-grab of the Bacardi pizza putting on a light show for me.

bacardi pizza flambe

Finally, the winning recipe.

 

No-Yeast, No-Rise Champagne Pizza Dough Recipe

Inspired by the Modernist Cuisine at Home Neopolitan Pizza Dough recipe.

 

INGREDIENT

QTY.

SCALING

PROCEDURE

Unbleached All-Purpose Flour

250g

100%

  1. Combine all ingredients in a stand mixer with the dough hook attachment installed.
  2. Mix on medium speed for 5 minutes.
  3. Let the dough rest in the mixer for 10 minutes.
  4. Mix on medium speed, again, for 5 minutes.
  5. For easier rolling, allow dough to rest for 15 minutes.  Divide dough into two equal parts, and roll out into 12-14” pizza crusts.
  6. Top to your liking, and bake in the hottest setup you’ve got until the crust is risen and the cheese is golden brown.

Champagne or Sparkling White Wine

155g

62%

Honey

10g

4%

Salt

10g

4%

Vital Wheat Gluten (Bob’s Red Mill Brand)

2.5g

1%

WRISE Microencapsulated Leavener

7.5g

3%

Go Grill a Pizza

pizza on the grill
If you asked me my favorite thing about summer, you could be sure that my answer would involve the words “grilling” and “pizza”.  Grilled pizza is an excellent easy supper, especially when you’re cooking with friends.  Go get some pre-made, uncooked dough and a few of your favorite ingredients and dive head-first into your relationship with the grill.  In the pizza above, a simple red sauce, some prosciutto, porcini mushrooms and fresh mozzarella make a great dinner.  Or, if you’re feeling less traditional, try out my other grilled pizza suggestions.