What does the term "reduction" refer to in cooking?

The term "reduction" in cooking specifically refers to the technique of thickening and concentrating flavors by simmering or boiling a liquid. When a liquid, such as stock, wine, or sauce, is heated, water evaporates, which leads to a denser, more flavorful mixture. This method enhances the taste of the dish as the flavors become more pronounced and complex through the reduction process.

In contrast, boiling without a lid does allow for some evaporation but is not the complete definition of reduction, as it doesn't inherently focus on improving the flavor profile of a dish. Chopping vegetables finely pertains to mise en place and preparation, playing no role in the reduction process. Lastly, adding water to dilute flavors directly opposes the concept of reducing, which aims to intensify their essence rather than lessen it. Thus, the correct understanding of "reduction" is about enhancing and thickening flavors by simmering the liquid until it reaches the desired consistency and taste.