Cool Stuff You Can Do: You Can Build a Stone Pizza Oven

A stone oven is relatively simple to build and can cook every bit as well as an expensive brick oven. It serves the purpose of a great grill that you can use year round. It also has the advantage of allowing you to bake awesome pizza in the summer without heating up your house. I make many different dishes in this oven including my beloved Rustica Shrimp Gorgonzola Pizza and the ever popular Smoked Turkey and Sausage Barbecue.

After you read this article, please see the follow on Build an Improved Stone Pizza oven.

Since rocks vary so much in size, I will give you general directions. You will need to fill in some of the gaps with your own ingenuity.

Ingredients

Rocks - I suggest you get them from your nearest construction site. They probably want to get rid of them anyways. Flat rocks are the best for rock walls, barbecue grills, and of course stone ovens. Do not use river rocks, as they tend to explode under extreme heat. The rocks should be roughly brick shaped, but they can be a variety of manageable sizes.
Soil or Dirt - It does not need to be high quality, just not sandy.High clay content is desired.
Water
A used smoker barrel or any barrel with the top and bottom removed

Theory of Operation

The oven operates on a basic furnace principle where the heat from the fire causes air to flow up the chimney. This causes more air to be drawn in which gets heated up and shoots upwards. In this way it creates its own draft. The taller the chimney, the greater the temperature difference between the top and bottom, the greater the draft.

The heat diffuser barrel spreads the heat out for move even cooking.

Directions

Site Preparation

In a level spot, far from the house, dig a rectangular hole 6 inches deep and 4 feet wide by 4 feet long. Fill with gravel. The gravel provides a stable platform for the rocks as well as helping to drain the oven in the case of a rain storm. This is your foundation.

Dig 2 4 foot long by 6 inch wide trenches in a down hill direction from the edge of the foundation. Fill the trenches with gravel. These are your oven's drains.

Mix the Cement

The cement is really mud with organic material mixed in to give it strength. This is basically the same principle as adobe bricks, but used between the rocks. You can also do crazy things like putting tulip bulbs in your mud, and yes they will grow out the side of your oven.

Use a large tub, I used my kid's old sandbox.
Dump in about 10 shovel fulls of loose soil. It does not have be great soil, but it is better if it is high in clay. Sand is no good
Mix in about 2 shovels of grass clipings. Even weeds will do the job here.
Pour in just enough water to bind the mixture into a thick mud. Don't overdo the water.
Mix thoroughly with your shovel, this will be a great workout.
Let stand for at least one hour. You will need a rest anyways.

Build the First Level

Never build more than 2 or 3 layers per day. The cement needs to set, and you need to rest and watch sports on TV anyways.
Build 3 walls, rock wall style, leaving the front open. The 3 sides should be close enough that the barrel rests on all 3 walls.
Continue building until the height is about 2 feet.
Rest the barrel on 3 sides.
Use a large stone to cross over the gap on the front side, make sure you use lots of cement to bond all surfaces.
Build more walls on all four sides of the barrel. Use plenty to cement between the barrel and the rocks.
Keep building until the walls reach the top of the barrel.

Complete the Oven

Build the back and side walls up for another 1-2 feet. Of course leave the front open. Remember to use plenty of cement.

Lay a large flat stone over the top to form the roof, bonding with plenty of cement. Make sure to keep a 6 incg gap open to the rear to form a chimney.

The chimney is very important, so be creative. You can use a steel stove pipe, but I chose to build it out of rocks.

After you have made the chmney cover the remainder of the gap in the rear roof with flat rocks and bond thoroughly with cement.

Cure the oven by running a fire in it for several hours. This will help the cement set. You can use crappy wood and even burn yard junk for this fire since you are not going to cook on it.

You may want to build some accessories for your oven. I made a heat proof door and an electric rotisseri. I will describe those projects for you on another day, meanwhile, enjoy your oven.