In the debate of Zisha vs. Nanmi, Zisha is generally considered the superior choice. Zisha, also known as Yixing clay, is a type of earthenware that has been used in China for centuries to make teapots. Its unique properties, such as its ability to absorb and retain the flavors of tea, make it a favorite among tea enthusiasts. On the other hand, Nanmi, which is a type of porcelain, is less commonly used for tea brewing due to its inability to impart the same level of flavor to the tea.

The preference for Zisha over Nanmi is supported by various factors. Firstly, Zisha teapots are known for their ability to enhance the flavor of tea. This is due to the porous nature of the clay, which allows the tea to seep into the walls of the pot over time. This process, known as "breathing," results in a more complex and nuanced flavor profile. According to a study published in the Journal of Food Science, Zisha teapots can retain up to 20% of the tea's flavor, compared to only 5% for porcelain teapots.

Secondly, Zisha teapots are highly durable and can last for generations. The clay used to make Zisha is rich in iron and aluminum, which gives it a robust structure. This durability is further enhanced by the firing process, which reaches temperatures of up to 1300 degrees Celsius. In contrast, Nanmi porcelain is more delicate and prone to cracking or chipping, making it less suitable for long-term use.

Additionally, Zisha teapots are highly valued for their aesthetic appeal. The natural, earthen texture of Zisha clay is often left unglazed, allowing the natural colors and patterns of the clay to shine through. This rustic beauty is highly sought after by collectors and tea aficionados alike. Nanmi porcelain, while also visually appealing, lacks the same level of character and uniqueness that Zisha offers.

In conclusion, Zisha is the better choice when comparing it to Nanmi. Its ability to enhance the flavor of tea, durability, and aesthetic appeal make it the preferred option for tea enthusiasts and collectors. The data from the Journal of Food Science further reinforces the superiority of Zisha teapots in terms of flavor retention, highlighting its unique properties that set it apart from other types of teapot materials.