How the Incas Stored Food for Years: The Qollqa System
The Inca developed a sophisticated system of state storage to provide food, raw materials, and ritual goods for the population and the imperial administration. The system, which is known through archaeology and through the accounts of colonial chroniclers, was organized by the central state and included thousands of storehouses, or qollqas, distributed across the empire. The qollqas were designed to preserve maize, quinoa, dried potatoes, dried llama meat, and other staples for years. The system also supported the imperial army, the mit’a labor system, and the aqllakuna, the chosen women who lived in cloisters in the major cities.
The building form
The qollqa is a small, single-room building, typically built of polygonal stone, with a half-buried floor, a single narrow doorway, and a stone or thatched roof. The walls are typically 0.6 to 1.2 meters thick, and the floor is sunk approximately 1 to 2 meters below the surrounding ground level. The doorway is small, typically less than 1 meter high and 0.6 meters wide, and is placed on the side of the building that faces away from the prevailing wind. The roof is typically a low-pitched structure of wooden beams supporting a layer of thatch, and the whole building is designed to be cool, dry, and well-ventilated.
The half-buried floor and the thick walls of the qollqa have a thermal effect. The temperature inside the building remains relatively constant, at approximately 8 to 12°C, throughout the year, even when the outside temperature varies by 20°C or more between day and night or between the wet and dry seasons. The temperature is maintained by the thermal mass of the walls and the surrounding soil, and by the ventilation through the doorway and small openings in the walls. The combination of low temperature, low humidity, and good ventilation is ideal for the long-term storage of grains and other staples.
The qollqa was a standardized form, with relatively small variations in size and layout from one site to another. The standard interior dimensions are approximately 3 to 5 meters in length and 2 to 4 meters in width, and the storage capacity of a single qollqa is typically 1,500 to 5,000 kilograms of maize, depending on the specific dimensions. The storehouses were typically built in groups, on a series of terraces, and the groups were located near the agricultural areas that they served and near the major roads that connected them to the imperial core.
What was stored
The qollqas were used to store a wide range of goods, including maize, quinoa, dried potatoes, dried llama meat, coca leaves, cotton, wool, dried fish, salt, and a range of ritual and ceremonial goods. The principal staples, however, were maize and dried potatoes, and the storage system was designed primarily around the preservation of these two crops. Maize was stored in the form of dried kernels, while potatoes were stored in the form of chuño, the freeze-dried potato product of the Andean highlands.
The process of making chuño was a key feature of the Inca storage system. Potatoes were spread out on the ground at high altitude during the cold nights of the dry season, and the alternating freezing and thawing converted the starches in the potatoes to a stable form that could be stored for years without spoilage. The chuño was then trampled to remove the skins, washed, and stored in the qollqas. Chuño was a principal food of the imperial army and the mit’a laborers, and the Inca developed an extensive system of chuño production in the high puna of the Andes.
Maize was stored in the form of dried kernels, typically in large woven baskets, and the qollqas were designed to keep the kernels dry and free from pests. The Inca were familiar with the use of natural insecticides, including the application of muña (a high-altitude mint) to the stored grain, and they used a range of techniques to keep the stored grain free from rodents and insects.
The state storage system
The Inca storage system was organized by the central state and was one of the most important features of the imperial administration. The state took a share of agricultural production as a tax, stored it in the qollqas, and distributed it to the population in years of poor harvest, as a form of insurance, and to soldiers and laborers on imperial projects. The colonial chronicler Pedro Cieza de León, writing in the 1550s, recorded that the Inca were able to feed populations for years from these state stores, and that the system was one of the principal reasons for the resilience of the Inca state in the face of drought, frost, and other natural disasters.
The storage system supported the imperial cult, including the maintenance of the temples, the aqllakuna, and the ritual calendar. The state provided food for the temples and their personnel, and the granaries were an important part of the imperial religious system. The qollqas were typically built near important religious sites, including the temples of the Coricancha, the royal estates of Machu Picchu and Ollantaytambo, and the religious centers of the provinces.
At Colcamayo, near Juliaca in the department of Puno, more than 600 individual storehouses held perhaps 5,000 tons of grain — the largest of the imperial granaries, and a site where the combination of low temperature and low humidity made the design almost self-operating.
The administration of the storage system
The storage system was administered by the qollqa camayoc, the master craftsmen in charge of the storehouses. The qollqa camayoc held positions of high status, and the storage system was one of the most important features of the imperial administration. The qollqa camayoc kept the storehouses in repair, recorded the stocks (in some cases using quipus), and released grain to the population in years of need.
The distribution of the stored grain was organized by a system of turns, in which each community in the region was allocated a specific time at which it could receive a share of the stored grain. The system was administered by the local ayllu, the kinship group, and the qollqa camayoc of the central administration supervised the distribution. The system was remarkably efficient, and the distribution of grain was generally equitable, with disputes being resolved by the local authorities and by the central administration of the empire.
The Spanish conquest disrupted the administration of the storage system. The Spanish made use of the Inca qollqas after the conquest, but they did not maintain the system in the same way, and the distribution of stored grain was gradually replaced by a system of tithes and tribute. Over the centuries, many of the qollqas have been destroyed, modified, or left to decay. However, several thousand individual storehouses are still in evidence across the Andean region, and the network of storage sites is one of the most extensive archaeological records of the Inca state.