Yacai is a traditional ingredient originating from Yibin in Sichuan. This pickled vegetable is made from the upper stems of mustard plant. The mustard greens are harvested in the 9th lunar month. The leaves are discarded, the stems are sliced into strips, and the strips are dried, then mixed with salt and fermented from 3 to 6 months in sealed containers.

They are then boiled with brown sugar and hung to dry again. Sichuan pepper, star anise, and other spices are added, and the mustard greens are fermented for another 3 to 6 months befor consumption. Yibin yacai is often used in stir-fries with vegetables and meat, and it's a crucial ingredient in dishes such as ganban sijidou (dry-fried green beans) and dan dan noodles.

Served as an appetizer, palate freshener, or a side dish, pào cài is a Sichuan-style pickle made with various vegetables, mostly Chinese cabbage, carrots, mustard stems, long beans, daikon radish, turnips, cucumbers, ginger, and hot peppers.

In Sichuanese cuisine, these crunchy, tangy pickles are always on hand, and almost every family keeps a large clay pot in their kitchen, filled with a variety of seasonal vegetables in a simple water and vinegar brine seasoned with salt, sugar, and Sichuan peppercorns. 

Even though sauerkraut is a German word meaning sour cabbage, Chinese sauerkraut or suan cai, sometimes also called xiān cài, is probably the very first version of sauerkraut, as it is known that the laborers who built the Great Wall of China ate it as standard fare over 2000 years ago.

In fact, sauerkraut is thought to have originated in the north of China among the Mongols, and was most likely brought to Europe in the 13th century with the Mongol invasion and the migration of nomadic tribes. Traditionally, suan cai from Northern China uses shredded napa cabbage, which is shortly blanched, salted, and then fermented in its own juice with the addition of rice wine, while in the southern parts of the country Chinese mustard greens are used instead. 

Zha cai is pickled stem of mustard cabbage from Sichuan. The stems are traditionally rubbed with salt and pressed in order to release excessive moisture. Later on, they get rubbed with spicy, red chili paste and are left to ferment in large earthenware vessels.

Zha cai can be used in a number of dishes and is usually braised, cooked, stir-fried, placed in soups, or consumed on its own as a pickle. The pickle is rich in umami and adds a flavorful savoriness to foods. It has a crisp, firm texture and a unique, sweet, spicy, and salty flavor.