How to Make a Simple and Rugged Tandoori Oven
You will need the following items to make the oven as powerful as possible. There is some room for variation that you can consider as you work through this project. However, you should stick with the items listed below for maximum efficiency and ease of use.
1 large metal garbage can
1 large terracotta flower pot
A grinder to form angles
A tape measure or ruler
The first step is to place the fire bricks on the bottom of the garbage can and create an even layer. You will need to cut the bricks into customized pieces to get them to cover the round base of the can. The best way to do this is to mark bricks with a line of chalk that will indicate where they need to be cut and trimmed. Take your grinder and cut down the bricks and set them aside. Fill the bottom of the garbage can with some sand to a depth of around 1 to 2 inches. Place the cut bricks on top of this layer and make sure they cover the sand and bottom of the can as much as possible. Cut or trim more bricks as necessary.
Fashioning the Terracotta Pot
The first step is to remove the bottom of the larger pot and set aside. Carefully mark the cut line a couple of inches from the bottom of the pot and grind away. You will need this bottom piece later, so be careful not to break it while cutting or removing from the pot.
The next step is to cut a vent hole in the side of the can, near the bottom where the bricks rest above the sand. Make the cut about the size of a brick. Cut out three sides and leave the fourth attached to the can. It doesn’t matter what side you keep attached as long as you can use the newly-created flap to regulate air flow and control the amount of heat in the oven. If you need more heat, peel the flap open. If you need less heat, push the flap in so less air can get into the oven.
Installing the Pot
Invert the pot and place it directly on top of the bricks on the bottom of the can, and make sure that the pot is centered. Take your vermiculite and pour it into the space between the outside of the pot and the inner walls of the can. You want at least three inches of vermiculite between the pot and can to provide maximum thermal efficiency. Fill the can with the vermiculite until it reaches about an inch below the top rim of the inverted pot. Since the pot tapers out as it gets closer to the bottom, the layer of vermiculite will be thinner. By the time it reaches the bottom of the pot, chances are that it will not spill out of the vent hole that you’ve made earlier. However, if some vermiculite gets through the space between the pot and can near the bottom, just ignore it as long as there is enough room for air to move through the system. Consider using a larger pot if there is too much space between it and the sides of the can.
Add the charcoal or other form of fuel that you are using to the bottom of the pot and let it rest directly atop the bricks. Start the fire and place the bottom piece you made earlier over the top of the inverted pot. Chances are that the bottom of the terracotta pot has a pre-drilled hole in the center. If not, make one so that air can vent through the system.
Remove the lid once the desired temperature has been achieved. Add food items to a skewer and place directly into the center of the pot. Cover if desired and cook away. The cover is primarily used to retain heat, but is normally removed during cooking. However, you can add and remove the cover as necessary to regulate temperature.
The material from the pot, vermiculite and fire bricks will all help to insulate the oven and contribute to an increase in radiant heat. You will be amazed at how efficient this system is by using the garbage can instead of a series of pots to make this oven. Not only will it generate more heat and use less fuel, but it will also be much more durable than the pot-only option.
Try it out for yourself and experiment with different fuels and cooking techniques. You will be amazed at how much heat can be generated and retained, and this oven provides a fantastic alternative to building a fire in order to cook your next meal.