What is a dirt oven? As the name implies, it is an oven made from dirt or clay. It was one of the antique appliances used in the country areas along with a fireside in the outside kitchen.
The oven was built on a base of 'board' (wood slabs) and dirt. The board was arranged to form a square base and covered with dirt/soil. The dirt chosen must contain as few stones as possible and more clay. Water was then added to make the clay more pliable and grass and cow dung were mixed in for added strength.
This mixture was spread over the wooden base to a height of 6"-8" and coconut husks were piled onto the base to form a dome shape. Tapia (a mixture of clay, grass and cow dung) is plastered over the dome and left to dry for several days. Cracks that appear would be filled in and left to dry some more. Two door spaces would be cut away from the clay dome and a piece of "barrel hook" (metal barrel hoops) would be butted in to reinforce the sides and top to prevent them from caving in. One of the doors would be a little bigger than the other since one is an entrance and as we call the other, an ash hole.
After the structure is dry it is now ready for firing up! The coconut husks are set alight, thus leaving a cavity. At the same time, the outer clay layer is baked hard leaving a durable structure. This process completes the making of the dirt oven and it is now ready for use.
FIRING THE OVEN FOR ITS FIRST BAKING
You need the following materials to heat the oven - the dried, woody part of coconut branches; dried coconut fruit Stalks ("grap" or "broom"); bramble (dried brush). These are packed into the oven and lighted, then left to burn to ash or coal.
The ash is pushed out through the ash hole and the oven is then swept with a black sage broom - black sage, because it doesn't wilt and it gives the oven a fragrant, herby scent. Flour is then sprinkled into the oven to determine the temperature: if the flour burns too quickly, the oven is too hot but if it browns slowly, the oven is ready for baking.
The dough that has been previously kneaded is placed on "fig leaf" (banana) for breads, while sweetbreads and cakes are baked in tins. These are packed into the oven with a pil which is a long wooden shovel or palette. The ash hole is then plugged with a wet crocus bag and a wooden door is fitted into the space and held in place by a stick. The front door is then positioned to ensure a tight fit and the contents are checked from time to time.
Source: Toco Folk Museum Quarterly Vol.1 No.2 1999 - written by Esther Springer Beckles