Pachamanca is the Quechua name for the ancient cooking method invented by the Incas. This method cooks foods at altitudes over 5000 meters (16,000 ft). Due to necessity, sometimes during the reign of the Inca Empire the people learned how to build a homemade pressure cooker. With the majority of the Empire residing in the high Andes,cooks learned how to provide food for both rulers and peasants. At high altitudes,the air is thin and boiling temperature very and low,thus cooking can become a long and arduous chore. The Pachamanca oven was created to shorten the cooking time by locking in the pressure and heat as well giving the food a unique flavor. A small hole dug in the ground is lined with rocks and built-up to form a structure resembling an igloo.A fire is lit inside for the stone structure for 1-1/2 to 2 hours.This heats the stones to such a degree that many may burst and tumble the struture. Thus an expert cook must be used to select the stones.The rocks in the structure are then removed and replaced with the food:potatoes,sweet potatoes,corn, and marinated meat,etc. The hot rocks are returned to the oven, intermixed with the food. Last to placed is the dessert of sweet cheese or pumpkin with brown sugar, known as "humitas". This is all covered with large green leaves to seal in the smoke flavoring. Then 4 to 6 inches of dirt is placed over the entire area and left for another 1-1/2 to 2 hours.The dirt seals the heated rocks and food underground.This same method is used today,allowing guests to talk about they want and drink chicha (an alcoholic beverage made of corn) or beer, while the food roasts in the pachamanca oven and comes out delicious. The ancient Pachamanca that was invented by the Incas is still in wide use today; although no patent was ever applied for! The next time you use your pressure cooker, remember the Incas: