What should a wine steward generally understand about wine?

A wine steward, also known as a sommelier, should have a strong understanding of how to pair wine with specific meals because this knowledge is essential for enhancing the dining experience. Pairing wine with food involves understanding the flavors, textures, and aromas of both the wine and the dishes served. By recommending the right wine, the steward elevates the meal, making it more enjoyable for the patrons. This skill includes knowing which wines complement and contrast the elements of different foods, creating harmony on the palate.

While the other options may also possess relevance to a wine steward's expertise, they are not as fundamental as the ability to pair wine with meals. For example, knowledge of the history of wine production, geographical origins, and chemical compositions can enhance understanding and might contribute to the overall knowledge of wine, but they do not directly influence the immediate experience of dining and wine enjoyment, which is the primary focus for a wine steward in a restaurant setting.