After his father flees to escape his debts, the century-old Zhou family tofu shop teeters on the brink of closure. Zhou Yuan, the fourth-generation inheritor, steps in at a critical moment. Facing a series of attacks, including thugs vandalizing the shop, malicious rumors spread by competitors, industry giants cutting off his soybean supply, and cheap counterfeits flooding the market, he remains committed to traditional methods without additives. Using his family's ancestral techniques of setting tofu with fermented sour whey and making amber-colored tofu with dry brine, he breaks through the obstacles and solves the challenge of standardizing and mass-producing this handmade intangible cultural heritage craft. In the end, he defeats noncompliant competitors at a tofu banquet attended by ten thousand people and successfully registers the sour-whey tofu-making technique as provincial-level intangible cultural heritage.