Parboiled rice is a type of rice, often white rice, which has been partially cooked during the milling process and then packaged for sale for use in homes and restaurants. The process was originally developed in Asian nations to simplify the process of removing the raw white rice from its husk and was later determined to have increased nutritional benefits as well. Though parboiled rice is often confused with instant rice, the processes by which they are prepared are quite different and parboiled rice can often require longer cooking times to properly prepare, rather than shorter cooking times.
White rice, once it has been gathered, is typically brought to a location for processing and milling before being packaged for sale and use in cooking. The processing and milling of the rice is intended to remove the grains of white rice from the harder husks that they naturally grow within. This is often a meticulous and time-consuming process, and machine milling can damage grains as they are removed from the husks, reducing the final quantity. Rice producers looked for ways to more easily remove the grains from the husks, while increasing the number of grains successfully retrieved during the process.
What was developed was a process in which rice grains, still inside their husks, were first soaked in liquid to begin to soften the husk. The rice is then steamed in a pressurized environment, before finally being dried out. At the end of this process the rice can be more easily removed from the husk, while the heating and cooling also serves to gelatinize the starches in the rice, making broken grains inside the husk often reform into whole grains during the process.
Once this process for manufacturing parboiled rice became popular, it was discovered that it also increased the nutritional benefits of the rice. The vitamins and minerals within the husk are loosened up during the soaking process, then released by the steam and pushed inward into the rice grains due to pressure during the steaming. This results in white rice grains that are much closer in nutritional value to the traditionally healthier brown rice.
Some people use the term parboiled rice interchangeably with instant rice, but this is inaccurate and they are two different processes. Instant rice is cooked in hot water just as rice is prepared in home and restaurant kitchens, then dehydrated. The instant rice is then “cooked” simply by rehydrating the rice for several minutes, and is then ready to serve. Parboiled rice, however, is not actually cooked during the process and can take longer to cook during preparation. In North America, many manufacturers also partially cook the rice after parboiling to make preparation for consumption faster.