Parboiled rice is that rice which has been partially boiled in the husk. The three basic steps of parboiling are soaking, steaming and drying. These steps also make rice processing by hand easier and boost its nutritional profile as well as change its texture.

About 50% of the world’s paddy production is parboiled. The treatment is practiced in many parts of the world such as India, Bangladesh, Pakistan, Myanmar, Malaysia, Sri Lanka, Guinea, South Africa, Italy, Spain, Thailand, Switzerland, USA and France. Rice is easier to polish by hand after parboiling but mechanical processing is harder since the oily bran tends to clog machinery.

Parboiling drives the nutrients from the bran to endosperm. Parboiled white rice is 80% as nutritional as white rice. The starch in parboiled rice become gelatinous and is then retrograded after cooling. The parboiled rice kernels should be translucent when wholly gelatinous

Parboiled rice takes less time to cook and is firmer and less sticky. In North America parboiled rice is either partially or fully precooked before sale. Minerals such as zinc or iron are added, increasing their availability in the diet.

In older methods, clean paddy rice was soaked in cold water for 36–38 hours to give it a moisture content of 30-35%,after which the rice was put in parboiling equipment with fresh cold water and boiled until it began to split. The rice was then dried on woven mats, cooled and milled.

In the 1910s Huzenlaub Process of parboiling was invented which held more of the nutrients in rice. The whole grain is vacuum dried and steamed. It was followed by another vacuum drying and husking. This process makes the rice more resistant to weevils and lessens cooking time.

In even later methods the rice is soaked in hot water, then steamed for boiling which only takes 3 hours rather than the 20
hours of traditional methods. These methods also yield a yellowish color in the rice, which undergoes less breakage when milled.