In the 1800s and early 1900s, making clay bricks was a labor-intensive process. Machines and automation technology were not yet available to ease the challenge. In the early Chicago brickyards, a shovel was the only way to dig clay out of the riverbanks. Deposits found along the Chicago River became a good source of clay. From there, the Chicago common brick was born, and millions upon millions of bricks were made.
The proper raw ingredients (river clay, bank sand) were blended into a brick mixture and then formed into a rectangular shape. Rows of new wet bricks were laid out in the sun to dry or in special buildings to prevent the rain from damaging the drying bricks. Getting turned halfway through the process to insure both the top and bottom sides dried out, raw bricks would harden after several days of drying.
Firing the Brick
The final step in the brick-making process was cooking the bricks in special kilns. Many of these old kilns looked like beehives, thus the name Beehive kilns. Thousands of raw bricks were stacked in the kilns in preparation for the burn. The circular shape helped keep the hot air circulating inside the kiln.
Once the fires were started, the temperature was kept at a low heat for several days. This allowed any remaining moisture from the inside of the brick to dry out. The temperature of the fire was then increased until it reached a very high point (1,500 to 2,000 degrees Fahrenheit). At this point, any remaining holes to feed the fire in the kiln were bricked over and the fire was allowed to burn out. The kiln was then left alone until it cooled off.
Today, It Is Impossible to Manufacture These Clay Bricks
This specific river clay or river sand is no longer available, and the process is also time consuming and expensive. We implement a patent process of layering refractory insulation underneath and over the clay bricks we use in our Chicago Brickhouse Ovens.
This allows our ovens to reach true Neapolitan-pizza-cooking temperatures of 900 degrees Fahrenheit in 45 to 60 minutes. This means you can make a true and delicious Neapolitan pizza in 90 seconds flat. Our clay-brick ovens use less fuel and retain heat for a longer period. After several hours of cooking and making delicious pizzas, you can close our custom-made iron door we provide for your oven. You can then return early the next day and bake bread for the remaining part of the morning. If you add several logs of wood after that, you can start cooking pizzas again.
Today, our competition molds their ovens using refractory castable concrete. This concrete foundation may take up to three to four hours for the inside of the oven to reach a cooking temperature of 900 degrees Fahrenheit. This same castable refractory concrete is designed to reflect heat, not absorb it, and in time, it this will cause it to crumble with repeated use.
The Chicago Brickhouse Oven will last for many generations.