I started the Pizza-Porta with a simple wedge with an open window in the front. If that had worked, this device would be so simple (and cheap to produce)! With the open window, it was impossible to control the airflow/temperature, so I added a door. The door gave me the ability control the airflow and still check and access the pizza. But, my pizzas were better, but not fantastic. The top-browning heat was still escaping out through the top chimney. One of those eureka moments led me to add a vent next to the door so that I could cap the chimney and trap the heat in the dome.
In rolling out this product in different grills and in different settings I have cooked thousands of pizzas in a number of different kamado style grills. Along the way I learned some setup tricks to get you started. Try these ideas as a starting point for your own pizza cooking.
Nothing stirs up more discussion than lump brand. There are a couple of attributes of charcoal that truly interfere with cooking pizza. The first is any odor that is created. Watch out for brands that create a great deal of flame even after being fully engulfed as they put off a chemical odor. The odor will be absorbed by the crust. The other challenge is lump size. Filling the firebox with huge chunks of charcoal seems to result in lower temperatures. It is critical to place larger pieces in the bottom so that you don't choke the airflow, but a mix with chicken-egg size lump seems to get hotter than huge logs. Conversely a bag of tiny chips makes a solid mat and chokes your airflow.
The intense heat of a kamado grill is the result of its airflow design. Air is sucked in the bottom to replace the air expelled out the top. The hotter it gets, the faster this air is expelled and faster it is drawn into the bottom. If the charcoal or deflectors or stones impede the airflow, it will impede this furnace tendency. Use a Kick Ash Basket as it is self-clearing when small chunks of charcoal drop toward the bottom. Also, overlap half-moon deflectors in the middle to ensure that there is plenty of space around the edges for airflow. Make sure that airflow gaps are wide to reach high temperatures.
One quick observation is that wind is not good for grilling. Try to position your grill so that wind does not blow into the top or side vents. Rotate the grill or place it around the corner of a building to shield it from direct wind.
There is a super-hot fire underneath the pizza stone. This is the source of all the heat, and unfortunately for baking, it is all concentrated below the cooking surface. To balance this concentration of energy, the grill must be set up so that the heat is reflected off the bottom of the pizza stone and passed around the edges to heat the ceramic surfaces on the sides and top of the dome.
The goal for a more Neapolitan style pizza is to have the dome temperature super-hot (>650F) and the stone oven floor nearly the same temperature. This of course is not the natural tendency of a kamado grill. The plate setter or the deflector stone is a great first step, but there a couple of cautions: 1) When it is placed legs up and set down in the three slots of the fire ring, the platesetter may limit your airflow, keeping the grill for reaching high temperatures. 2) Never set the pizza stone directly on the plate setter. This will just transfer all of the heat to the pizza stone making it too hot to cook. Even adding ceramic parts like bricks or tile between the deflector and the stone will transmit energy into the pizza stone. It is critical that there is a kind of escape valve for this heat energy in the form of an air gap. This gap will allow the heat from the top of the plate setter to dissipate before reaching the pizza stone. Using the stainless grate and some additional material like pipe fittings or balls of aluminum foil is a great solution. (The cast iron grate does not serve very well to provide this air gap because its mass carries heat from the edges into the bottom of the pizza stone.) The air-gap is the first step, but for additional deflection, shielding can be added under the pizza stone. A heat shield needs to reflect radiant energy and shed energy. Using an aluminum foil disk underneath the pizza stone is a great addition to an air gap. This thin layer reflects the radiant energy that comes off the plate setter and keeps the pizza stone temperature a bit lower. An aluminum pizza pan also serves a similar function of creating a radiant barrier that keeps the pizza stone from overheating.
Stands and racks
There are a number of stands and racks available. Any device that lifts the pizza stone off of the plate setter and increases the air gap can be beneficial. A double rack like the Pizza-Porta RCL rack, serves this purpose and also allows more capacity. Having two stones gives flexibility in cooking between the top and bottom stones. The bottom stone is closer to the heat source so tends to regain temperature more quickly. When cooking a number of pizzas it is helpful to use the bottom stone as the first placement for a pizza. More about this under heat retention.
There is variability in pizza stones. The kamado manufacturers all provide a type of stone that is heavy duty enough for 700F + degree cooking. Some kitchen supply companies make pizza stones that are for home ovens and only stand up to 500F degree pizza cooking. The importance of the stone is to provide a surface that will retain enough heat to cook the bottom of the pizza. The porosity of the stone is claimed to benefit the crust by drawing in moisture. Buy a stone that is heavy enough to withstand high temperatures and will provide a suitable surface for your cooking style. Thermarite is a more durable material than firebrick. Beware of pizza stones that are larger than the diameter of the platesetter/deflector as they will block airflow and they will receive energy directly from the fire without the benefit of deflection.
Heat Retention in a Pizza Stone
Each raw pizza placed on the stone will bring the cooking surface down 30-40F degrees. In a wood-fired oven, the pizzaioli will spin a pizza in place to take advantage of this. It is important to consider this when planning for a party. If the stone will be sitting empty in the grill 10-15 minutes between pizzas, the temperature will climb between each one, so you may want extra deflection or more space below the pizza stone so that it does not exceeded your desired temperature. If you want to cook a number of pizzas in a row, you may want to allow the stone to get a bit hotter by using less deflection.
Lighting a kamado grill for pizza is not a trivial detail. There are differences between lighting for a 250F degree cook and a 600F+ cook. For pizza at 600F you need a big fire. Use an absolutely full load of fresh lump. Then, light the lump in a number of places on the top so that the fire can spread to engulf more of the fuel. Allow the fire to get established as you are loading in all of the internal components. Leave the top dome open for a few minutes and let the fire get big.
Here are some pointers to setting up the Pizza-Porta in your kamado grill. The best way to get up to pizza temperature is to light the lump in a number of places around the edge. Next, place the racks and stones. Leave the dome open for a few minutes to get the fire established. Finally, place the Pizza-Porta with side vents closed in the grill and close the dome. Leave the chimney vent and bottom vent open fully for maximum airflow. The temperature will rise slowly as it is heating the ceramic of the walls, deflectors, stones etc. Once the grill reaches 400F watch closely as the temperature often hits a sweet spot and jumps. As the grill approaches 500F degrees, close off the top chimney vent and open the Pizza-Porta vents. The temperature may drop a bit before climbing again toward 600-650. Once your stone is over 400F you can begin cooking. The stones and ceramic walls take about 20-30 minutes to soak in enough heat to start cooking. Some grills, even of the same brand, seem to heat faster than others - get to know your oven.
Cooking on a kamado grill is a truly rewarding experience. The grill is very forgiving and most everything you do will result in great cooking results. Pizza seems to be the most challenging food on this style of grill because heat is lost every time the dome is opened. This guide is a starting point. Take your time, have fun, and develop your own solutions.
Make sure to seek advice from bloggers and chefs who make a living making great pizza. Wood-fire pizza places are a great place to learn.