YAMAMOTO CO., LTD.

About 75% of milled rice is starch. Raw starch does not taste good and is difficult for digestive enzymes to process. When heated in water, rice starch gelatinizes, becoming easy to digest and delicious.

Rice cooking gelatinizes starch by heating it with an appropriate amount of water. Raw rice is cooked through the processes of washing, adding water, soaking for a certain time, heating, and steaming.

Washing Rice

Rice is washed in water to remove rice bran or dust from the surface of milled rice, changing water several times.
It is better to wash rice and change water quickly in the first wash, because rice absorbs the water and takes on the flavor of bran.

When rice is washed, it also absorbs water and becomes about 10% heavier.

Wash-free rice (Musenmai) does not require washing or fewer washing because rice bran is thoroughly removed by refining the surface in the milling process.

Adding a Proper Amount of Water

Purpose of Adding Water

The amount of water must be sufficient to gelatinize rice starch. At the same time, all the water added must be absorbed in the rice by the end of cooking. A grain of cooked rice requires appropriate hardness and stickiness.
The amount of water added must be decided to satisfy all these conditions.

Insufficient Water

According to a study on gelatinization rates of rice obtained by added water ranging from 100% to 150% of the weight of rice, little difference in the gelatinization rate was observed just after cooking, regardless of the amount of water. However, 14 hours later, the less water was added, the more the gelatinization rate fell. The result indicates that the dispersion of rice starch micelles was insufficient because of the small amount of water added.

In addition, rice cooked with water weighing less than 120% of the weight of rice has little adhesiveness, and also has a poor texture.