The purpose of any grain storage facility is to provide safe storage conditions for the grain in order to prevent grain loss caused by adverse weather, moisture, rodents, birds, insects and micro-organisms like fungi.
In general, it is recommended that rice for food purposes be stored inrather than milled rice as the husk provides some protection against insects and helps prevent quality deterioration.
However, when rice can be stored as brown rice, 20% less storage capacity will be needed. Brown rice is rice grain with its hulls removed but not polished. Under tropical conditions brown rice has a very short shelf life, approximately two weeks.
Rice storage facilities take many forms depending on the quantity of grain to be stored, the purpose of storage, and the location of the store.
Storage systems can be through bag, bulk, or hermetic containers.
Good storage systems include (1) protection from insects, rodents and birds, (2) ease of loading and unloading, (3) efficient use of space, (4) ease of maintenance and management, and (5) prevention of moisture re-entering the grain after drying.
Safe storage of rice for longer periods is possible if three conditions are met:
The longer the grain needs to be stored, the lower the required moisture content will need to be. Grain and seed stored at moisture contents above 14% may experience the growth of molds, rapid loss of viability and a reduction in eating quality.
Good hygiene in the grain store or storage depot is important in maintaining grain and seed quality. To maintain good hygiene in storage:
Rice grain isand in open storage systems the grain moisture content will eventually equilibrate with the surrounding air at the so called equilibrium moisture content (EMC). High relative humidity and high temperatures typical for the humid tropical climate lead to grains absorbing water in storage and to a high final moisture content.
In many tropical countries, the equilibrium moisture content is above safe storage moisture levels.