What does it mean to “reduce” a sauce?

To “reduce” a sauce means to cook it until it thickens or its flavors become more concentrated. The process of reduction involves simmering or boiling the sauce to evaporate some of its water content, leading to a richer taste and a thicker consistency. As the liquid reduces, the flavors intensify, which enhances the overall taste of the dish. This technique is commonly used in culinary practices to create sauces that have a more robust and concentrated flavor profile, making them more appealing and complex.

In contrast, increasing the volume, diluting with water, or adding spices do not achieve the same desired outcome as reduction. Each of those actions may alter the viscosity or flavor of a sauce in different ways, but they do not specifically focus on intensifying and thickening it through the evaporation of liquid.