Name one environmental factor that can affect coffee growth.

Altitude of the growing area is a crucial environmental factor influencing coffee growth. Coffee plants thrive in specific altitude ranges, which can significantly affect their growth and bean development. Higher altitudes generally lead to cooler temperatures, which can prolong the maturation period of coffee cherries. This extended maturation can enhance the complexity of flavors and acidity in the coffee beans, contributing to higher quality in the final product.

In contrast, the size of the coffee beans, the method of packaging, and the type of coffee grinder used are not environmental factors. These aspects relate more to the processing, storage, and preparation of coffee rather than its growth conditions. Thus, altitude stands out as a key environmental determinant that directly affects how and where coffee can be cultivated.