German green coffee sorter made iron in 1950 is green iron with a small motor next to it. Put 50 kilos of green coffee beans into a conical funnel that is attached to the table surface. The adjustment lever has an arc iron piece for attaching light bulbs, with 5 white-prong outlet plug and a flat coffee bean outlet. In the middle of the sorting table, there is a coffee sieve tray to remove damaged beans. The sorting table has four legs, and at the bottom has a foot pedal when the power is off.
Classification of coffee beans, a quite important stage of processing and preserving coffee, is to remove defective beans, is to classif size of the beans, using a sorter with different sieve holes.
Types of sorters for size and grains, density sorters for classifying and selecting following density, and color sorters neither improve nor compromise the inherent quality of grains. They only have effects of classifying coffee into different quality levels in order to reduce impurities and defective beans in commercial coffee, so it is necessary to pay attention to storage conditions and quality variations. Because of different reasons, especially in terms of price, that coffee is stored from processing to exporting for a different long or short time. During the preservation process, humidity and ambient temperature in the storage are the main factors involved in the deterioration of grain quality.
Whether the grains are degraded quickly or not depends on the moisture of the grain put into storage. This degradation is caused by the changing process of physics, chemical, and biological or destructive creatures.
To ensure long-term quality maintenance, coffee when stored should have grain moisture of less than 13%, and the air’s relative humidity must be balanced with the moisture of beans depending on the ambient temperature. If the moisture of beans is high, coffee can be attacked by insects or molds reducing the quality that is manifested by signs of discoloration, beans first change from gray-blue to white, and the mixed water is not pure taste. In 1910.