Reduction (cooking)

Lore & Background

Reduction is performed by simmering or boiling a liquid, such as stock, fruit or vegetable juice, wine, vinegar or sauce, until the desired concentration is reached by evaporation. This is done without a lid, enabling the vapor to escape. Different components of the liquid evaporate at slightly different temperatures, and the goal is to drive away those with the lowest evaporation points. While reduction concentrates flavors, reducing too much can decrease all liquids and leave a sticky, burnt coating on the pan if not stirred constantly.

Reader's Guide

Reduction is a fundamental technique in cooking, used to create concentrated flavors and thicker textures in sauces, soups, and syrups. Sauces such as brown sauce, béchamel sauce, and tomato sauce are simmered for long periods—from 1 to 10 hours—but not boiled, as simmering develops maximum flavor and allows impurities to be skimmed off. Boiling would diffuse impurities, resulting in bitter taste and unclear stock. Broths are also simmered rather than boiled for the same reasons. Common preparations include consommés, gravies, gastriques, pan sauces, and syrups. The process relies on evaporation, and in some cuisines, additional methods such as adding starch or sugar, or using natural gelatin from collagen-rich ingredients, are employed to achieve thickening.

Did You Know?

• Reduction is performed without a lid to allow vapor to escape.
• Boiling a sauce during reduction can diffuse impurities and cause a bitter taste.
• Sauces like brown sauce, béchamel, and tomato sauce are simmered for 1 to 10 hours.
• Over-reduction can leave a sticky, burnt coating on the pan if not stirred constantly.