/kloc-In the middle of the 9th century, the declining Russian aristocrats brought квас brewing technology to Central Asian countries and China, Xinjiang, Ili Valley, Altay, Tacheng and other places for the first time. In the following 150 years, ethnic minorities in these areas, such as Russians, Uighurs, Kazakhs, Hui and Han, especially Yili, brewed квас in their own ways, and kept technical exchanges with each other, and finally made квас. In Xinjiang, квас has many names: Gewaqi, kawas, Gowasu, local beer, mead and so on. Douchi made and preserved by traditional techniques has a short shelf life. Even if it is stored in a heat preservation barrel now, it can only be stored at room temperature for about three days. When drinking kawas, you should observe whether it is transparent and whether the smell is light. If it is turbid and has a strong fermented taste, it means that it is not fresh kawas, and its taste is poor, so it is not suitable for drinking.