At No. 26 Zhengjiepu in Yilong Town, the weathered grey flagstones of Yang's Ancestral Hall hold a six-hundred-year-old secret. Originally constructed during the Ming dynasty as a communal shrine for the local Yang clan, this brick-and-timber compound features a classic one-entry courtyard surrounded on three sides by wood-framed halls. At the center of the courtyard sits a quiet, basin-sized stone well. This well taps into a natural reservoir of underground acid water. Rich in unique minerals, this water serves as a natural coagulant, curdling soy milk without chemical gypsum or brine. It gives Shiping tofu its characteristic dense, elastic, and non-collapsing texture.

In 1956, the new government repurposed the ancestral hall into the state-owned Shiping County North Gate Tofu Factory, the county's earliest bean-product enterprise. When privatization threatened the factory in the late 2000s, the workers themselves purchased the enterprise. They chose to preserve the demanding, manual hand-making traditions inside these historic walls.

In May 2024, the local government integrated the site into its Pan-Museum Group urban-renewal initiative. Today, the building is protected as a County-Level Cultural Relics Protection Unit and operates as the Shiping Tofu Museum, the first and only tofu-themed museum in Yunnan Province.

Visitors can touch the cool stone of the ancient well, grind yellow soybeans on traditional mills, and watch steam rise from boiling soy milk. By using the courtyard's legendary acid water to curdle their own fresh tofu, guests participate in a living culinary lineage. The ancestral hall remains a place of active labor, where the past is tasted, touched, and kept alive by human hands.