Portable Propane Pizza Oven Build and Cook

So a while ago I made a pizza oven from a beer keg and while it worked awesome, it was a bit too small and heavy. It could cook pizzas with zero recovery time between pies. Since my success with that, I figured I could make one from scratch and mimic some of the retail models out there.

Do a search for portable pizza oven and you get many different models to pick from. They all seem to cook a nice pizza but one key thing for most of them is they have a recovery time as the floor of the oven cools down once you cook a pizza and sometimes it can take several minutes to get back up to temp. Also heating up the oven can usually take about 30 minutes regardless if it's wood-fired or propane powered one like the Ooni Pro.

So my idea was to build off my previous design, have jet burner(s) in the rear with a heated oven floor with tube burners. That way I could independently control the heat of the floor and dome temperature.

Also I think this project fits well for the multi-discipline contest as this project covers metal-working and cooking, so please vote for me if you think this project is awesome!

I'll try to include everything I used but I might miss a few things.

Materials:

• 304, 20 gauge stainless steel sheet metal
• 1" x 1/8" flat bar stainless bar stock
• 1" x 1" x 1/8" angle stainless steel
• 1" round stainless tubing
• 1/4" round stainless rod
• 1/4" steel plate
• 1/2" x 1" NPT pipe nipple
• 1/2" NPT pipe fittings (elbow, coupler, etc...)
• 2.5 " stainless square pipe schedule 40
• copper tubing
• 1/8" flare fittings
• Wall tile
• Silicone sealant
• BBQ thermometer

Tools (affiliate links):

• Welder (MIG set up for stainless or stick welder with SS electrodes)
• Sheet metal brake/bender
• Drill and Drill bits
• Angle grinder with cutting discs
• Metal cutting bandsaw (optional)
• Power file
• Flaring tool
• Deburring tool
• Wetsaw for tile cutting
• Diamond drill bits
• Wrenches and small hand tools
• Safety equipment, eye protection, mask, welding shield, common sense

Here are is a video of the whole build and also some videos to help with other parts of the build, all written directions are included in this Instructable too on the subsequent steps. This project is built upon other projects to make it whole.

My initial design was to have a sheet metal stainless steel shell with a liner but I learned quickly that stainless steel warps very easily when heated, it has a low coefficient of thermal conductivity. So it was important to have bends to keep the stainless steel ridged.

Bending stainless steel requires a metal brake so I also made one of those for this project that made bending the metal a breeze.

Ideally I would have a bead roller to help make the panels ridged in some places.

So here is my build process and I kinda designed as I went so my end design is very elegant but it has evolved as I ran into problems that I had to solve.

If I were to rebuild this oven again I would incorporate more bends in the sheet metal to keep it from warping. What I did was add some angles stainless steel to make the body ridged but this in turn added weight. I'll talk about this more at the end of the build.

All of the sheet metal used for this project was 20 gauge 304 stainless steel .

I started by making the outside shell of the oven. Using the metal brake, I made four bends on a piece of stainless sheet metal to make a partial rectangle with the bottom left open, I forget the exact dimensions.

Bending stainless is a lot harder than bending regular sheet metal, especially if the stainless hasn’t been annealed.

Next I welded on a bottom frame made from stainless 1” angle to the outside shell. I thought about making removable legs but ended up welding some 1” stainless tubing for the legs.

The inside liner of the oven was also made from stainless sheet metal, it started off as a rectangle but I cut the back 1/3 of it off and added a sloped top where the flame will contact the top of the oven. Also welded to the top was a piece of mild steel that acts as a flame shield.

After some testing, I realized that because the top is a long flat surface, the stainless steel warped like crazy to counter act this I welded some pieces of bracing across the top of the liner.

In hindsight I could have welded them to the inside or if I was to redesign it, I would add some beads with a bead roller to strengthen flat areas or I would redesign with extra bends as this makes the metal more ridged.

For the floor of the oven I contemplated using stone or cordierite, which can with stand high heats but I wanted a floor that I could heat up independently from the rest of the oven. So I went with a mild steel floor, google an article on Serious Eats for some testing they did on different types of pizza “stones”. Also I used mild steel instead of stainless steel because mild steel has a higher coefficient of thermal conductivity.

The floor is one large piece of 1/4” steel plate with 1” sides welded on, this is to help prevent warping once the steel plate heats up. This was sized to fit between the inside liner.

It was then soaked in vinegar overnight to remove any of the mill scale, a tough scale left on hot rolled metal. The next day after a scrub and wash the steel looks super clean. Then it was coated with some canola oil and heated for a while to create a non-stick rust resistant coating. Just like seasoning iron or steel cook wear.

This oven is starting to get heavy but all of the parts of the oven are modular and removable so transporting it won’t be much of an issue.

Parts of this design will change after some testing with the burners. So next is making the burners.

I have made many propane burners in the past, ideally I would like to have the oven wood fired but after some trial and error from previous testing, I determined that an oven this size is too small to be powered by wood or charcoal for a consistent cook without having to wait 30 minutes to get up to temperature. Propane will provide the super hot heat required to cook a pizza quickly but it’s also a moister heat as one of the by products of burning propane is water so it needs adequate air flow/venting or else you get condensation build up, it's a balance.

There will be four burners for this oven, two tube burners on the bottom and two jet burners (ended reduced it down to one) in the body of the oven. I will go over quickly how I make them but I have other Instructables that go into detail on how to construct these burners.

If you don’t know how to work around propane I highly recommend you do not attempt to make these burners yourself, if you do proceed, I take no responsibility for your own personal safety. Use common sense and use personal protection gear, at a minimum safety glasses and non flammable clothing and gloves.

Tube Burners: These burners are very easy to make and will be used to heat the floor of the oven, I used two pieces of stainless steel tubing, then cut 1 cm slits in them using a bandsaw, an angle grinder with a cut off disc can be used too. For the intake I used a reducing bell for iron pipe, this was welded to the stainless tube. To get propane into the tubes I made a jet nozzle/orifice from some 1/8” brass pipe fittings, with the orifice being made from a brass endcap with a 1/16” hole drilled out. The 1/8” brass pipe was then threaded into a piece of steel that had a hole drilled and tapped to the 1/8” NPT thread. This assembly was then welded onto the reducing bell. See this Instructable on how to make these burners step by step. To install the floor burners I welding some brackets to the base of the main part of the oven body. Holes were drilled and tapped so I could remove the burner assembly if needed. Link to build

Jet Burners: These burners are also very easy to make and produce a ton of heat and will power the main part of the oven, I ended up making two burners so I could keep the flame spread out across the rear of the oven. The burners are made from 2.5” schedule 40 stainless steel square pipe, while over kill it was the only size stainless steel pipe I could find locally. I used a piece of 12” 1/2” black pipe as the feeder pipe for the burner, this pipe had 1/16” orifice holes drilled into it. After some testing any smaller orifice hole with the pressures I was running at blows out the burner. The square tubes were welded over the orifice hole and then connected to propane using some pipe fittings for testing. Link to build

Note: after some testing once , I ended up removing one burner and centering one burner on the rear tube. Two burners proved too powerful so I ended up having to run the burners at a reduced power which was not optimal for the venturi effect, there by the burners ran really rich which caused a lot of carbon build up. Your mileage may vary depending on the regulator used as well.

Installing: The main burner was installed in the rear of the oven by cutting a hole in the main body and the liner of the oven. The burner was tilted to blow slightly upward towards the flame shield. Then some stainless bar stock was tapped and welded to the body of the oven, these are brackets to install the burner. To the jet burner some bar stock was welded to line up with the brackets, then holes were drilled to align with the tapped holes in the bracket.

Both burners run off one BBQ propane regulator all tied together using copper lines and flare fittings. I wanted the propane valve to control the burners to be at the front sides of the oven. To do this I had to run copper lines from the regulator to split off and feed each burner assembly separately taking into account the valves. I had to be creative for this but using bendable copper lines made this easy.

After some testings and realizing that the stainless steel was warping due to not enough bends to give structure to the outside body, I addressed it by making a frame to strengthen it. While functional, it's not the most aesthetically pleasing oven to look at. I fixed this by covering the outside frame of the oven with large wall tiles. This also provides an additional layer of insulation.

I cut the wall tiles to size using a wet saw and attached them by using silicone sealant as it will withstand high heat. Let set for at least 24 hours.

The oven door is a piece of tile with a open cut to access the inside of the oven. Some 1" stainless steel bar stock was glued to the tile using silicone sealant, making a frame for the door. The frame had two pieces of round stainless rod welded to the top.

These pieces of rod will insert into the front of the oven frame where two corresponding holes were drilled, this makes a sturdy and simple removable door. Lastly a hole was drilled in the center of the tile with a diamond bit to fit a BBQ thermometer. The thermometer was glued in place with silicone sealant.

To assemble the oven: the liner is inserted into the body of the oven. Then the floor is inserted into the oven and then with the oven door to follow. Before cooking anything in the oven, the whole oven was washed down with soap and water to remove any grinding dust and contaminates.

Before I cook anything in the oven I washed and cleaned all surfaces and then heated the oven to dry it out and seasoned the oven floor with some canola oil. Just like seasoning a cast iron frying pan, this will provide a nice rust free non-stick surface. It will need to be re-coated with oil after every use to prevent rusting if storing the oven outside due to do to changes in temperature causes condensation to build up on the floor.

The oven is now finished! The heat up time is less than 5 minutes and really what takes the most time to heat up is the floor of the oven, I can have the body well above 900F in a minute. I’ll end up using this oven far more often because it doesn’t take long to heat up.

Just because I now have an oven that can reach super hot temperatures doesn't mean I can make good pizza's. The oven is just a tool, so I had to do lots of testing by cooking many breads and pizzas, which was an awesome thing to be testing but not particularly good for my waistline :)

Time to cook some pizzas!

First real cook was I made some garlic naan bread. The recipe I used was from my favorite Indian Curry cookbook, “The Curry Guy”. The naan turned all puffy and blistery in under 2 minutes! This oven gets hot! I cooked a few different breads and pizzas in the oven over the last few months. The ability to adjust and tune the burners separately really helps dial in the crispness of the crust and the brownness of the top.

The high heats this oven can reach can easily cook Neapolitan style pizza with nice spotted crusts which is what I am aiming for. I haven't tried cooking any fish or steaks in it on a cast iron pan but I know it should work well. I just need to improve my pizza making abilities now. The dome temps can easily max out the thermometer and I estimate the temp gets as high as 900-1000F. I am loving this oven and it heats up in less than 5 minutes, saving fuel and my time!

Pizza Dough Theory

The key thing about pizza dough is it depends on the structure you are aiming for. I wanted a nice airy crust with a nice chew, that is accomplished by using a dough with a good protein content like bread flour. However using regular all purpose flour I was able to get excellent results. After much testing I realized that the time spent kneading of the dough is so important to build the gluten structures that make an awesome pizza crust, more important than even the type of flour.

The best pizza doughs are made from just a few ingredients: water, yeast, flour, sugar/honey and salt. If you have access to 00 Italian flour, this is the ultimate for making pizzas. 00 flour is milled finer and absorbs water at a different rate than regular flour, it works to a nice smooth dough and is by far the best flour I have used to make pizzas but it costs more and is harder to find.

So after a lot of testing of different pizza dough recipes, here is the one that I found to give me the best results for a Neapolitan pizza:

Dough Recipe

Ingredients:

• 1 litre of Water room temp
• 50 grams Olive oil
• 25 grams Sea Salt
• 1500 grams Flour, 00 or All Purpose
• 10 grams of Honey or Sugar
• 5 grams of Dry Yeast

1. Put water and yeast in a bowl, then add the honey, mix well. Honey or the sugar helps the yeast to get started.
2. Add 1000 grams of flour and mix for about 5 minutes. This is the 1st fermentation.
3. Cover with a towel and rest for 1 hour.
4. Dump the dough onto a floured surface and then add the remaining flour, salt and olive oil and mix well. Knead for 15-20 minutes until smooth and elastic. Can also use a stand mixer with dough hook.
5. Form into a ball and cover with little olive oil and let rest covered for 1 hour.
6. Get a sheet pan and dust with some flour. Cut into two long strips with a scraper.
7. Then cut into 200 gram pieces and form into a balls tucking it into itself. Place onto floured pan and cover with a bit of flour and cover with plastic wrap.
8. Ferment for 6-8 hours at room temp. Then place in the fridge if saving to use later.
9. When working with the dough, make sure it's at room temperature, flour it well and use a scraper to pick up the dough and then press and stretch by hand.

Toppings

The toppings are also a whole other important topic, to cook a Neapolitan pizza it is super important not to use too many toppings. The pizza cooks in 1-2 minutes and if it's loaded with too many toppings it will burn before it cooks completely or else the heat needs to be turned down and then it's not going to have the airy hollow crunchy dark spotted crust that makes it a Neapolitan pizza.

Tomato Sauce

The tomato sauce I used is very simple using San Marzano tomatoes:

Pour one large can San Marzano tomatoes and sauce into a large bowl and to the can add:

• 1 handful of Fresh Basil
• 1 tablespoon Sea Salt
• Add a few tablespoons of olive oil

Use an immersion blender and blend up and down the can, don’t over blend the sauce. You want the tomatoes to have tiny pieces still in the sauce.

Cheese

The cheese used was a pizza mozzarella that had a very high fat content, I didn't have access to buffalo mozzarella which I will try some day. Also cheese like buffalo mozzarella is packed in water and will not burn as quickly, so if you want a more burnt cheese pizza use mozzarella that is drier.

Pizza Assembly

So to assemble my pizza I floured a ball of pizza dough well and worked the dough with my hands to stretch it out. No rolling pin required if the dough was made properly, and don't fight the dough, just let it rest and work it gently. Remove the excess flour and then top with a light coating of pizza sauce and cheese. I'm not a fan of basil so I didn't add any to my pizzas. Immediately move the pizza on to a pizza peel and launch into the pizza oven that has been preheated to HOT.

Cooking

The oven should be heated to 800-1000F, once the pizza is in the oven, it's very important to not walk away. After 30 seconds the pizza should be ready to be rotated. Turn the pizza using a long BBQ flipper so the less cooked sided is facing towards the flame of the oven.

I check the bottom of the pizza to see how well it is cooking, it should have nice dark spots at the 45 second mark. If it doesn't I turn down the main burner and let it brown up on the bottom. If the bottom is cooking too fast, I use my BBQ flipper to lift the bottom off the floor of the oven and let the toppings cook.

At the 1:30-2:00 minute mark the pizza should be cooked, I gauge and adjust the cooking as needed, once cooked the pizza is served!

A few tips on how to keep the pizza from sticking on the pizza peel:

• As SOON as the pizza is made, put it on the peel and launch into the oven. The longer the pizza is left on the peel the more time it has to stick because the moisture from the pizza sauce can absorb through the dough. Also depending on the temp of the ingredients condensation can be an issue causing the dough to stick.
• Using a wood peel can buy some more time as the peel can absorb some moisture
• Using a perforated peel can also help prevent sticking. Use a nice smooth jerking motion to slip the pizza into the oven, don't hesitate!
• Don't rely on too much flour or corn meal to keep it from sticking, it makes a mess and will burn on the bottom of the oven since the oven reaches temperatures higher than a regular oven.

There are so many different ways to make pizzas and types of pizzas, it's really fun to test and try them out but for this Instructable my main reason for making this oven is so I could make Neapolitan pizzas which this oven will happily do. I even made dessert pizza with chocolate!

The final result was an amazing pizza with a nice chewy crunchy crust, achievable only when cooked at a super high heat and with proper pizza recipe and technique! Who would have thought that something so simple as pizza has so many little technical aspects that need to be performed properly to achieve an amazing pie! Such a fun experience learning all aspects of what goes into a good pizza.

Hope you enjoyed this Instructable and consider following me here and on my YouTube channel.

Lastly please vote for me in the multi-discipline contest if you like this Instructable!