In general oil production, whitish sesame seeds are usually not hulled. However, it is highly recommended to hull the sesame seeds when eating directly. The reason is that the fiber and oxalate content in the seed skin or cuticle of sesame is high, so that its oil and meal cannot be used as human protein resources, and can only be used as cattle feed or oxalate. Besides, the skin of the sesame seeds also has a bad effect for the taste of sesame seeds. Therefore, when sesame is used as a food, it is usually required to be hulled. The hulled sesame not only tastes smoother, but also more easily for the nutrition to be absorbed by the human body. 

There are two main methods of hulling the sesame seeds:

WATER HULLING

The water hulling uses dilute alkaline solution to separate the the skins from the sesame seeds. First, the seeds will soaked into the alkaline solution. The alkaline solution will make skin of sesame seeds softened and easy to be separated. After washing off the residual alkaline solution, the sesame skins will be released from the sesame seeds by vibrating and rubbing. To separate the sesame skins from the products, sieving and washing are the two most common methods. Finally, the hulled sesame seeds is dried and packed. 

DRY HULLING

Dry hulling uses no water or chemical products. It just heat the sesame seeds to make it drier, The sesame skin will be crispy during this process. Then the dried sesame seeds will be sent to hulling machine. With subsequent friction and bumping, the sesame skin will fall off from the sesame seeds and then be separated.