Granaries are stone buildings designed to store and preserve threshed grain or animal feed. Grain must be kept from moisture for as long as possible to preserve it in good condition and prevent mold. Granaries are erected away from inhabited buildings, as any chimney or hearth represents a source of danger to the dry grain they contain.
Granaries are not used for the storage of flour. Persons wishing to obtain grain from a granary must present their own sack; burlap is best. A 40 lb. sack of barley, corn, oats, rye or wheat grains varies from 70 to 100 c.p.
Despite the tremendous importance a granary has for a community, each is managed privately in Europe by a freemason. India assigns the management of grain as a matter of caste, while China's bureaucracy serves the equivalent storage of rice production. A single granary building as described below, is managed by a single family of 3-8 persons, with three full-time labourers, adding 6-11 persons to the population (d6+5). The labourers dwell in a nearby hovel, whilst the owning family have a timbered house.
Newly harvested grain brought into a granary tends to contain excess moisture, so it's traditionally spread in thin layers on a dry barn floor, to aerate it thoroughly. This can take between 5 days and six weeks, depending on the climate; if not dry by six weeks, 10% of the yield must be culled from the remainder and the grain taken to a drier, underground space. If one isn't available, the whole crop may be lost. Once the grain is sufficiently dry, it can be transferred to the granary.
In the granary, grains are stored in massive earthenware jars specially designed to maintain a cool, dark environment. Baskets and sacks do serve, but it's best to transfer grain in these to jars after the first year. If managed well, grain can be stored for seven years, which is vital given the dangers of one or more years of drought and lost crops during that time. A community's welfare depends upon the careful management of its existing grain, which is expected to last much more than a single year.
To preserve grain, it has to be moved, or "poured," over and over again, to keep it dry. Thus the granary keeper is kept working by this necessity.
To store one full year's supply of grain from the equivalent of three type-7 or type-6 hexes, and provide room inside, a single granary building must have a minimum volume capacity of 3000 cubic feet. This makes a building 12 ft. tall, 15 ft. wide and 17 ft. long. One small granary of this size is built upon 12 base pillars supporting a plank floor and frame. Brick construction is preferable, with a thatched or shingled thoroughly-enclosed roof. Circulation of air from below is used to maintain the dryness of the grain.
Spoilage of grain is notably heavier in years of abundance, whereas during times of famine the lesser amount of grain that's left can be more closely managed. More than one granary is often built (1 chance in 4), so that in case of damp, any given building can be emptied and dried out. This second usually empty building doesn't increase the number of resident persons.
Portions of the interior can be blocked by removable planks into bins as high as the ceiling. As planks are removed, the upper grain is allowed to fall into a long trough from which it can be scooped for movement elsewhere by wheelbarrow. This allows space for earthenware jars, which aid in distribution, transport and sale. Thus the granary possesses a door, as floor space exists to enable movement inside. Temporary bins can be loaded from above through an upper window or hatch. In times of great abundance, the door can be blocked either from the inside or outside, allowing the whole granary to be filled from floor to rafters.