Japan's Rice Innovation: Prewash Rice (musenmai)

Drycleaning Rice: The Toyo Rice Center process retains flavor and nutrition

The idea of washing rice may be alien to Western people who are used to getting rice out of a box. But in fact, from India to Korea, it is a pan-Asian practice. Rice grown and packaged in America go through a cleaning process which reduces the need for washing, but imported rice have plenty of starch in a powder form clinging onto the kernels. The taste of the rice improves with washing. With the additional starch, the texture of the cooked rice would be gummy and glue-like. Visually, well washed kernels gleam when cooked as opposed to being dull from the powdery residue. Short-grain Japanese rice, long-grain Southeast Asian rice as well as Indian basmati rice are all usually washed.

Toyo’s original machines to measure  the moisture and clarity level of rice kernel
Toyo’s original machines to measure the moisture and clarity level of rice kernel

The process of washing rice only takes about five minutes, but in the winter, it can result in freezing hands and numbed fingers. To avoid this chore, Japanese rice producers have created rice that has been prewashed before bagging. There are several methods of doing this but consumers feel the taste is sometimes compromised without the starch to protect the kernels. The Toyo Rice Center in Saitama Prefecture, located north of Tokyo, believes they have mastered the technology to produce the best tasting rice without the need to be washed.

Since machines to prewash rice are very costly, small growers from all over Japan ship their products to this center where the unhusked grain is processed to be supermarket ready.

The friction of a mortar banging against the rice takes away the bran from the kernel
The friction of a mortar banging against the rice takes away the bran from the kernel

Prewash rice is a misnomer for what Toyo Rice Center does because “wash” invokes the image of water. Unlike other types of prewashing technique which does use water which results in dirty runoffs into the oceans, using Toyo’s method, the bran powder residue turns into fertilizer and animal feed, leaving no wastage. In fact, Toyo Rice Center’s BG (Bran Grind) prewashed rice has been awarded by the Environmental Ministry for its environmental friendly manufacturing. In 1991, Toyo introduced their technology to rid off the bran residue by using friction from gently rotating the rice kernels – similar to a drum type dryer. Then the machine separates the rice from the bran powder. The “dry washed” rice is then bagged and ready for delivery.

Quality inspection
Quality inspection

Along the way, we see technicians in lab coats working with various small machines and gadgets, measuring the quality of the rice kernels. Many devices are developed in-house by Toyo to specifically ensure that rice processing would enhance the taste and leave nutrition intact. Indeed, this is perhaps the most impressive part of the tour. To see many Toyo employees work to innovate – even in the smallest way – to improve their business. While some breakthrough may only have minor benefits, Toyo employees have developed a new product that is increasing in popularity. Recently, even convenient store chains offer rice balls using Toyo’s Kinme Mai, “golden center rice.” While the nutritious benefits of brown rice (genmai) is well known, it is still rather difficult for many to accept its coarser texture. The Kinme Mai however tastes like white rice (hakumai) yet provides 70% more fiber, five times more glucose yet fewer calories than white rice.

The lack of nutritious value of polished white rice has been recognized by health conscious consumers. Overseas lovers of Japanese cuisine especially demand healthier fare and many restaurants will offer sushi made from brown rice. But for many – including chefs – are ambivalent about how the texture of brown rice takes away from the delicate flavors of Japanese cuisine.

Samples of cooked Kinmemai rice
Samples of cooked Kinmemai rice

Kinme Mai is produced using Toyo’s unique rice polishing technology to retain the nutrition loaded golden center of the rice kernel while removing the outer bran shell. This results in twice as much vitamin B1 and vitamin E and significantly more fiber, magnesium and niacin as white rice. Recent research by cardiologist Dr. Satoru Eguchi from Temple University School of Medicine in Philadelphia, and recognized by the American Journal of Hypertension, has shown that this type of rice helps maintain blood pressure level and protect the arteries of the heart from narrowing. Not currently available outside of Japan, but the demand for Kinme Rice may soon take the world by storm.

The Toyo Rice Center is not the obvious choice for a factory viewing but it is a fascinating look into how a mid-size company continues to innovate to stay competitive and productive.

The Tour:

Toyo Rice’s Yoichi Sakaki demonstrates the optimal way of boiling rice.
Toyo Rice’s Yoichi Sakaki demonstrates the optimal way of boiling rice.
  1. The tour begins in a conference room where a video of Toyo’s prewashing process is shown. Then the guide demonstrates the optimal way of preparing rice before boiling. The emphasis is on soaking the raw rice until water is fully absorbed in every kernel so they are plump when cooked. The guide also demonstrates how much bran residue there actually is by taking the water from rinsing three cups of rice and heating up the liquid until it evaporates and all that remains is fried glue.
  2. Then we put on white lab coats made of paper and hair caps. We also go through an air curtain to ensure we are clean.
  3. The first place we visit is where unprocessed rice is unloaded into the factory. There is a clear heavy plastic curtain to prevent birds from trying to access the grain. The first of the heavy machines takes the husk off and then debris is separated from the grain. The amount of debris – leaves, twigs and pebbles – mixed in is astounding. Rice kernels rattles while going through the huge pipes where the rice is transported to another part of the factory for prewashing.
  4. The rice prewashing machines resemble long tubes rotate the rice kernels for a 20-minute cycle. Then the rice kernels are transported to be bagged and the bran residue are separated to be dried and turned into fertilizer and animal feed.
  5. Then the tour group returns to the conference room and get to sample various types of rice.

Toyo Rice Center – Kanto Factory 7-5 Nissai Hanamizuki Sakado, Saitama Prefecture, 350-0269 Phone: 049-288-4700

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