It is a symbol product of chinese national geography, and GB is a recommended national standard, which is not mandatory. Wuchang rice grows in the southwest-facing C-type basin in wuchang city, Heilongjiang Province, where the active accumulated temperature is 2-3 degrees Celsius higher than that in other areas, which is beneficial for rice to reach the active accumulated temperature required for high-quality rice.

Rice grade:

First-class rice: the back ditch has no skin, or the skin is wireless. More than 90% of rice embryo and rice grain surface cortex are removed, and the crude fiber and ash content are low.

Second-class rice: the back groove has skin, and the processing accuracy is lower than that of first-class rice, and the rice embryo and grain surface cortex are removed by more than 85%.

Third-grade rice: the back furrow has skin, more than 80% of the grain surface cortex is less than one fifth, and the rice is high in crude fiber and ash.

Grade 4 meters: there is skin on the dorsal sulcus, and less than one third of the grain surface cortex remains, accounting for more than 75%. A large number of cortex and aleurone layer are retained, so the crude fiber and ash in rice are the most.