Most of the nutrients in purple cabbage are water-soluble. If boiled, the nutrients in purple cabbage will be greatly lost. Purple cabbage contains no harmful substances, and it can retain its original taste without blanching. Blanching water may make the taste worse. When making cold purple cabbage, you can peel it off one by one, soak it in light salt water for15 ~ 20 minutes, then take it out, rinse it and cut it into filaments.