Black sesame can only be fully effective after nine steaming and nine drying. After nine steaming, the nutrients in sesame seeds are fully decomposed, and the greasy feeling is reduced, which is easy for human body to absorb; After nine days of exposure, sesame gets the energy of the sun, which is beneficial to human body.

Ancient herbal works such as Materia Medica recorded that black sesame seeds should be steamed and dried for nine times to increase the effect of blackening hair and tonifying. Tao Hongjing, a famous medical scientist in the Northern and Southern Dynasties, solemnly warned future generations that those who eat flax and take black color should steam nine dew and cook it with bait. Break the valley, live forever, and satisfy hunger.

Although it is easy to get, scholars can't always get it, what's more? Unfamiliar steam makes people uncomfortable. "Compendium of Materia Medica" and "Canning Dafa" also pointed out that it is uncomfortable to steam black sesame seeds for nine times.

It's best to buy black sesame seeds that can't be broken after nine steaming and nine drying, which can prevent sellers from cheating and make their own patterns.