Rice milling transformed from early man-power and animal-power to hydraulic operation. Later, mechanical milling emerged. By then, rice milling yield greatly exceeded the quantity attained in the previous stages. Now, rice milling factories have entered “computerized and one-line operation stages.” Other than higher rice milling yield, quality is also better controlled. Lian-Fa Rice Milling Factory in Houbi Town is a new type of rice milling factory. It has the latest equipments and cleanliness is observed. It is the place for many agricultural groups to visit. With Lian-Fa Rice Milling Factory as an example, let us take a look at the new rice milling factory operation methods.
　
◆《Quality Classification Testing, Weighing, and Temporary Storage》
Peasants had either dried rough rice/paddy under the sun after harvest or sought outsource peasants with driers in the past. Rice was then sent to a rice milling factory. However, most new rice milling factories now have drying equipments so rough rice/paddy is delivered directly to the rice milling factory after harvest.
After rough rice/paddy is taken to the rice milling site, the rice milling factory first conducts batch rice/paddy quality testing using Rice Quality Tester and Water content tester. Lian-Fa Rice milling is also equipped with a “Residual Pesticide Rapid Testing Station Pesticide Residue Rapid Test Station” which strictly monitors quality. After rough rice/paddy testing, trucks enter the factory for weighing. They then enter the material unloading opening to unload. Rough rice/paddy dropped on the ground will be sent to a wet barrel (wet grain temporary storage barrel) using an elevator for temporary storage.　
　

Weighing	Drying by heat

◆《Drying under low temperature》
The rough rice/paddy in the wet barrel is transported to the drier by the elevator where drying operations are initiated. During which time, rough rice/paddy first passes through the precleaner to remove impurities such as twigs, leaves, and stones. According to General Manager (GM) Chen of Lian-Fa, drying temperature is regulated as to the temperature of the day. Drying is usually done at 40 ℃. If the temperature is too high, rough rice/paddy will be burnt. In addition, rough rice/paddy turns up and down inside the drier like frying rice in a pan. It has to be constantly turned over to ensure even distribution of heat. After drying, samples are tested using the Rice Quality Tester to confirm quality.
Generally speaking, private grain and public grain drying level vary. Private grains are not stored over extended periods of time and are sold to the public, so, there are demanding requirements for the taste. For this reason, the water content of rough rice/paddy is dried to 14.5 degrees. This not only ensures the best taste, it is less likely to crack during rice milling. As for public grains, they are normally stored for over a year; the water content should not be in excess. Therefore, it is usually dried to 12-13℃ for easy storage.
　
◆《Freezing under low temperature》
After drying by heat, rough rice/paddy is sent to respective freezing barrels for storage. The temperature inside each barrel is maintained at 10-12℃. A freezing barrel is a storehouse with air-conditioning. The entire equipment is made of large temporary storage barrels and air-conditioning. You may wonder why rough rice/paddy is not just stored inside storehouses. Instead, large sums of money are spent to purchase freezing barrels to store it. There is a reason behind this. Dried rough rice/paddy is first stored. It is milled whenever needed. The longer rough rice/paddy is stored, the less tasty it becomes. In order to maintain rice quantity, storage at low-temperature is a better method as food freshness can be preserved.
　

Freezing barrel under low temperature	Computerized temperature control

Although a freezing barrel has great capacity, the problem of space inadequacy may still be faced during peak season. In times like these, jumbo bags” are used to store rough rice/paddy. The capacity of a jumbo bag is normally 1 ton. Since, the preservation results of “jumbo bags” are less ideal than freezing barrels, rough rice/paddy is usually milled and stacked in bags. Lian-Fa Rice Milling Factory places importance of storehouse ventilation in order to maintain public grain quality. There are also ventilation holes in grain stacks to dissipate heat. After all, storehouses and freezing barrels are different, thus, public grain usually tastes less delicious.
　

jumbo bag	Public grain storehouse

◆《Temperature regeneration》
Rough rice/paddy inside the freezing barrow should be temperature regenerated before milling it into brown rice or milled/polished rice. Factory staffs first transport rough rice/paddy inside the freezing barrel in amounts required into the temperature regeneration barrel. This way, rough rice/paddy is less likely to be subject to breaking during the rice milling process. Temperature regeneration usually takes about 6 hours. If rice milling is conducted in early morning, temperature regeneration has to start in the middle of the night. It is convenient to measure rough rice/paddy needed through a “flow meter.”
　
◆《Grain hulling》
After rough rice/paddy is temperature regenerated, it is ready for dehulling. By this time, rough rice/paddy first passes through a precleaner [to remove cords, coarse substances, and waste substances etc.], and a destoner [to remove sand, stone, cement, metal, and plastic etc] where foreign substances are further removed. It then enters the huller to remove hulls. Dehulling usually takes several milling sessions to complete to complete remove hulls. Hulls are separated in the “Grain separator”, and transported by an elevator to a chaff barrow for storage. As for brown rice, the impurities are further removed and sent by an elevator to the brown rice storage barrow.
　

Ddehusker/dehuller	Vibrator

◆《Rice refining》
Dehulled brown rice then enters rice refining procedures. First, brown rice enters the rice refining machine for rice refining. Then a vibrator is used to sieve fine bran. In conventional rice milling factories, the rice refining procedure ends here but modern rice milling not only places emphasis on yield, it also takes note of quality. Therefore, there are other follow-up sieving and selection actions taken.
Milled rice/polished rice after sieving fine bran is sent to the rice washing barrow where fine crumbs and adhered fine bran on rice surfaces are washed off. Milled rice/polished rice after rice washing is quickly sent to a “Color sorter” for sieving and selection. The Color sorter selects rice grains by means of optical principle [undesirable looking rice or rice worm-bored rice] and eliminates them. This way, milled rice grains appear lustrous and rich which guarantee sales.
　

Rice refining machine	Color sorter

After color sorting, milled rice/polished rice passes through the “sorter”, the “roller”, and the “rice washer” again. Then, the “vibrator” will sieve broken rice. The entire process is repeated sieving using different machines. Perhaps you wonder why there are so many sieving procedures. In fact, they are there to ensure each milled rice grain is both delicious and good-looking.
　

◆《automatic meter packaging, vacuum packaging, product freezing》
“Vibrator” sieved broken rice falls into a broken rice barrel. Finished products (milled rice/polished rice) is sent to the finished product barrel ready for packaging. Modern packaging is controlled by an” automatic meter.” The computer precisely sets quantity output unlike conventional rice milling factories that have scales at exit points to weigh.
For 1kg or 2kg small packages, Vacuum Procedure is frequently performed. This procedure is simple. Packaged rice is placed inside a “vacuum packaging machine.” The machine automatically pumps air inside the bag out and seals it. This way, the rice in the bag is kept under oxygen-free condition. It not only prevents dampness, oxidation, products are also kept for longer periods of time without being spoilt.
　

automatic meter packaging	Vacuum packaging
Product freezer	Product transported in a freezer vehicle

　
◆《New type of rice milling factories that place importance on quality》
From the descriptions above, it is found that both the new and old types of milling adopt similar processes. However, new type of rice milling place importance on quality. As a result, both rough rice/paddy and packaged rice are kept under low temperatures to maintain taste. The rice polishing process repeatedly “sieves” rice to mill intact and consistent finished product. It is no wonder old type of rice milling factories are no competition.