Rice is one of the most commonly consumed edible grains. In order for rice to be suitable for human consumption it must be processed in a number of ways. There are several rice milling machines that convert raw rice into the grain that is commonly seen in supermarkets around the world. Likewise, several different kinds of rice can be produced out of the same grain using milling machines in different ways. The most common form of rice is white rice, which is also the most processed form of rice.
The rice milling process has a number of steps. After rice has been harvested and dried it must be separated from additional debris. Large mechanical separators sift and filter out the rice; this is the first step in rice milling.
Following the separation process, the rice must be hulled. In this process, the outer shell is removed from the rice. Large rice milling machines perform this task by using a large rotating blade that removes parts of the hull as the rice passes through the machine. The hull of the rice grain contains fats that may rot or mold in storage. The rice that does not go through the hulling process at all or is only partially hulled is sold as brown rice.
White rice will generally go through a hulling machine several times before it is ready to reach the next step in milling. This ensures that the hulls are completely removed from the rice. Rice hulling also performs some of the separating process as well, and air is blown over the rice to remove dust, dirt and broken pieces of rice. These two milling machines are sometimes combined into a single machine in order to save space and make factory operations more efficient.
The polisher is the last in the series of rice milling machines. Hulled white rice is placed in the polisher and rotated against a screen. As the rice rubs against this screen, it is smoothed more than even in the hulling process. When the rice leaves the polisher it is brighter white and may be slightly translucent.
Rice milling machines are increasingly being combined into single machines. These machines are adjustable so that they are capable of producing brown and white rice. While most of the world’s rice is still prepared for consumption and storage using hand tools, combination rice milling machines make it more affordable for people to produce large quantities of milled rice quickly and efficiently.