We aim to explore the prerequisites for corporate sustainability from the perspective of non-formal institutions such as culture. Specifically, we seek to investigate whether and how Chinese tea culture influences corporate social responsibility (CSR). We have developed an OLS regression model to examine the relationship between tea culture and CSR, and our findings indicate that local tea culture yields positive effects. To address endogeneity concerns related to this correlation, we employed the local geographic slope as an instrumental variable for tea culture. Subsequent research highlights that the female executive, serving as a mediator variable, represents the primary mechanism influenced by tea culture. Furthermore, our study demonstrates that tea culture exerts a more significant impact on small and medium-sized enterprises as well as state-owned enterprises. Overall, this research contributes to the literature on the determinants of CSR from the vantage point of informal institutions, offering a fresh perspective for exploring the economic ramifications of tea culture for both academia and practitioners. Moreover, it furnishes valuable insights for advancing the sustainable development of enterprises.