At the winter wedding banquet, Chang's Vermicelli Workshop was publicly questioned about why their vermicelli costs eighteen yuan per catty. He neither argued nor surrendered, only rubbing open a handful: "This is cassava." The banquet table was lost, regular customers left, he pulled the vermicelli cart to the great market, testing it by boiling it publicly, not a single strand breaking. From loose sales to prepayment, from refusing to hang the merchant firm's sign to demanding back his reputation, a cart of wrong cassava compensated for a vat of vermicelli. When cheap vermicelli hung the sign "Chang's Vermicelli Workshop", he only asked for black and white on paper to question the origin, keep the vat number, test by boiling publicly, and write clearly the daily production. Eighteen yuan per catty, holding on until early spring without rising.