Because hot and sour powder is a snack in Sichuan.

Hot and sour rice noodles originated in western Sichuan, which is a traditional snack in Sichuan, Chongqing and Guizhou provinces, and belongs to Sichuan, Chongqing and Guizhou snacks. Its characteristics are hemp, spicy, fresh, fragrant, sour and oily but not greasy. The main powder of hot and sour powder is made of sweet potato, sweet potato and pea in proportion, and then it is made by traditional manual leakage by farmers. Hot and sour powder originated from the southwest folk, and it was made from local hand-made sweet potato powder. Its flavor was named after its outstanding hot and sour taste.