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Portable Brick Ovens by David S. Cargo
So, why would you want a portable brick oven? Why would you want any brick oven?
For most people in my classes, the answer seems to be wood-fired oven pizza. Some people want to bake some bread as well, but almost everybody wants to make pizza in a wood-fired oven.
A home oven is probably too small and too cool to have the capacity and temperature to make pizza like you would make in a wood-fired oven, which can make pizzas at temperatures as high as 1000 degrees F. (Any temperature in the range of 650 to 1000 works, but pizza cooks faster at higher temperatures.)
My oven designs can be used to build ovens that can bake 40 individual-size pizzas per hour.
There are many different kinds of wood-fired ovens. Some of them are made from brick. Some of them are made (mostly) from clay.
Brick ovens can be massive, permanent ovens, but they can also be mobile, by being built into a truck, bus, or on a trailer.
Most brick ovens are permanent, but some are designed to be temporary.
Some temporary ovens are made with stacked bricks.
There are different advantages and disadvantages to every type of oven.
Portable Brick Oven Advantages
This section describes the ovens that people learn to build in my classes.
Fast
Compared to anything but a complete prebuilt oven, portable brick ovens are the fastest to build.
You should be able to build a small oven in one hour. The large oven may take you about two hours. (It helps a lot to have somebody to hand you the bricks as you need them.)
There is another way in which the portable oven is fast: Once you decide to build one, it’s relatively quick to get the bricks. Assuming you are in the Twin Cities area in Minneasota, just call Smith-Sharpe Fire Brick Supply and tell them how many bricks you need. (Tell them I sent you.) They have them in stock. (Smith-Sharpe is not open on Sundays, so you can’t just order them the day after class.)
In other areas of the country, you would need to find a different firebrick distributor.
Once you have the bricks, you could build your oven the weekend after you take the class.
Simple
Portable brick ovens are about as simple as possible to build. You don’t need any expensive tools.
- You don’t need a masonry saw.
- You don’t need a cement mixer.
- You don’t need any metal cutting tools.
- You don’t even need any trowels.
As well as not needing those tools, you don’t need the masonry skills. You don’t need to know how to mix mortar or mortar bricks together.
To make a flat, level place to site the oven, it helps to have a level, a shovel, a two-by-four, and some sand.
After that, building the oven is a simple matter of following the diagram that shows where the bricks need to go.
Portable
If you build any kind of permanent oven, it will be pretty much a permanent fixture. Because of their size and weight, permanent ovens are pretty much stuck wherever they were made. (It might be possible to move one with really heavy-duty moving equipment, but not easy.)
The portable brick oven comes apart almost as easily as it goes together. If you built in the wrong spot or you want to put it into storage, you can just take the oven apart brick by brick and store it or rebuild it as appropriate.
The small oven weighs about 1300 lbs. The large oven weighs about 3600 lbs. Moving all of those bricks can be a chore, but at least it is possible.
Adaptable
How can a brick oven be adaptable? It can be adaptable because it is possible to change it after it is built.
Changing location was covered by having it be portable. Beyond that, the portable brick oven can be changed by adding more brick and rebuilding your oven to be bigger, either with a larger hearth floor or thicker walls. You could even make it smaller.
The supplied designs for the class include four different sizes: small, small pizza, medium, and large. Other design variations are possible.
It is possible start with a small oven and then add more bricks to move up to any of the larger sizes.
The two most popular sizes are the 3-wide pizza oven and the 4-wide oven.
Recyclable
If you find that you are using your oven a lot, but that you want to replace it with a permanent oven, you can reuse the firebricks in your new oven. (You can keep using the portable oven until the base for the new oven is finished.)
Cheap
The portable brick oven is cheap compared to anything except a cob oven. (Cob ovens are primarily made from clay soils, which are usually dug up on site. Cob ovens are about the cheapest ovens, and I have a special link collection about them.)
Because my portable oven designs use no mortar, and only firebrick, you sidestep a lot of costs for tools and supplies.
Permanent ovens may cost anywhere from $2,000 to $10,000 (or more), depending how much you build yourself, and how much you buy premade.
Portable Oven Disadvantages
My portable brick oven design is definitely not the best possible oven design, so it is only fair to enumerate its disadvantages.
Little Insulation
My portable oven design uses some insulating bricks on the bottom layer to help the hearth hold heat. (Even that insulating brick is optional.)
The sides and top of the oven provide thermal mass, but do not provide insulation.
That means that cooking time is more limited than with a permanent oven that has insulation.
After firing for 4 hours it should be possible to bake pizzas and bread for at least 1 1/2 hours.
If you need to bake for longer than that, moving to the next size up oven would let you keep a fire going in the back of the oven to sustain heat for longer.
Low Hearth Height
For simplicity and speed, my portable oven design uses a trivial base (either patio pavers or concrete construction blocks). That makes the height of the hearth very low compared to how permanent ovens are usually built.
You can build a base if you want to, but I suggest building your oven near where you are going to build the base so you can use it while you build your base (which will take more time and added money). You might as well get some use from your oven while the base is being built.
Temporary
A portable brick oven is not permanent. That can be a disadvantage if you want something durable.
(It might be an advantage if you need building permits for something permanent or if an oven would make it harder to sell a property.)
Note however that while it’s “temporary” that it’s not of particularly limited life. One oven built by one of my students for a retreat center near Ely, MN, has been in use since 2011. He told me that it gets used 15-20 times per summer.
No Door
Since the whole oven is built from individual bricks, it should be no surprise that the oven door is also made from individual bricks. It works, but there are other alternatives. I recommend a piece of HardiePanel big enough to cover the oven doorway.
Features
These are the characteristics that define my specific family of oven designs.
Door Width
In order to limit some of the heat loss, the oven door width is just a bit over 14 inches wide, big enough to get a 14-inch pizza peel through the door. This is not the oven you want if you want to make 16-inch pizzas.
That also means that you can get a Tuscan grill through the door so you can grill inside your oven.
Door Height
The lore of wood-fired ovens suggests that the door height of an oven should be 62 to 64 percent of the vault height, citing Rado Hand.
Despite building from whole bricks, the door height for my design is 67 percent, not too far from the ideal. The door height is 10 inches and the vault height is 15 inches.
Hearth Sizes
The portable oven designs all use whole brick, and optionally some square half-bricks (which can be simulated in some of the designs).
Since the size of typical firebrick is 9 x 4.5 x 2.5 inches, many horizontal oven dimensions are going to be multiples of either 4.5 inches or 9 inches.
The hearth sizes for my designs are:
- 18 x 18 inches (small oven)
- 18 x 27 inches (small pizza oven)
- 27 x 27 inches (medium and large oven)
Those hearths might seem small, but in practice they are big enough to do a lot of baking.
With good fire tending, the hearth on these ovens can be heated to a temperature of over 900 degrees with a 4-hour fire, hot enough so that you can cook many small items quickly.
The hearth of the small oven is big enough to do 20 to 40 individual-zize pizzas in 1 1/2 hours. (This does require an efficient production line.) You can fit three pizzas in the small hearth at once.
If your production line is not so efficient, you can go up one size to the small pizza oven, which has 9 more inches of hearth depth so that you can keep some fire going while you are baking, extending the time when baking is efficient.
At one of my classes we built a small pizza oven and kept the fire in the back going for two hours. We could have baked 40 pizzas an hour with the oven temperature being pretty stable over that length of time. (In class we baked 14 pieces of naan, 10 pieces of pita bread, and 9 pizzas in about 40 minutes.)
Wall Thickness
The portable oven designs have two different wall thicknesses. The walls of most of the designs are 4.5 inches thick. The large oven design takes that up to 9 inches thick. That provides additional thermal mass, making the large oven slower to heat and longer to cool, making it better suited to baking a lot of bread compared to the other designs.
External Dimensions
The exterior size of the ovens varies according to the hearth size and wall thickness. All the ovens are about two feet high (or a bit more, depending on what is used for a base).
The footprints of the ovens are as follows:
- 27 x 36 inches (small oven)
- 27 x 45 inches (small pizza oven)
- 36 x 45 inches (medium oven)
- 45 x 54 inches (large oven)
Operation
So how do my portable brick ovens work for making pizzas?
Firing
I recommend firing the oven for four hours before baking. If the wood is good, and the fire is built right, you should be able to heat the oven up to over 900 degrees by that time. (In some cases we have gotten the pizza oven hearth hotter than 1000 degrees in four hours.) (The larger ovens actually have more room and proportionally fewer bricks, so with a good fire you should be able to get hotter than that in four hours.)
At that temperature you should be able to bake a pizza in about two minutes.
With a 4-wide oven and aggressive fire tending, you should be able to get it to pizza temperature in 2 and a half hours.
Capacity
The small oven and small pizza oven can hold up to three small pizzas at once. It does take some dexterity and practice to get the pizzas in and out of the oven, but the class demonstrates what you need to do.
In practice, a 3-wide pizza oven is easiest to use with one pizza at a time, and you can use the extra depth of the hearth for more fire to keep the oven hotter longer.
Baking Time
The time for a pizza to cook depends on how hot the oven is and how thick the pizza is.
You have to learn how to judge how long your pizza will take, and that takes practice.
It also depends on how cooked you want your pizza.
Pizza Process
My experience has been that people will take longer to put a pizza together (roll the dough, add the sauce, toppings, cheese, herbs) than to bake it.
Therefore it’s a good idea to have multiple dough balls ready, multiple peels available, and multiple people putting the pizzas together to maximize use of the heat of the oven.
Because these ovens cook so fast, you cannot assume that raw meat will be cooked safely. You either need to go with vegetarian pizzas or use prepared meats that are already cooked and safe to eat.
Tricks and Tips
In some ovens, the hearth might cook the crust faster than the top. In that case, you can use a technique know as “doming” where to pick the pizza up on a utility peel and hold it near the top of the oven. That cooks the top while the bottom has been removed from the heat of the heart.
The opposite situation can happen as well; the top could be cooking faster than the crust. We have discovered in that case, you can hold the utility peel over the pizza. That allows the crust to cook more while the top of the pizza is protected from heat from the top of the oven.