A sous chef notices that the flavor of the soup has changed. What is the most likely reason for the change in flavor?

The most likely reason for the change in flavor of the soup is that the purveyor changed a critical ingredient manufacturing source. When a supplier alters the source of an ingredient, such as a specific brand of stock, herb, or vegetable, it can significantly impact the flavor profile of the dish. Variations in farming methods, processing, or even the terroir (the environment in which the ingredients are grown) can lead to changes in taste and aroma that are often noticeable in prepared foods. Therefore, regardless of the cooking techniques or equipment used, if the fundamental ingredients are different, the resulting flavor will likely change as well.

New cooking equipment or reheating the soup multiple times might affect texture or temperature, but these factors are less likely to alter the fundamental flavor of the soup as drastically as a change in ingredient sourcing. Following a modified recipe could lead to variations, but if the basic recipe has not been altered, the taste should remain relatively consistent barring other influencing factors.