What is Reduction?
Reduction is a technique that involves decreasing the volume of a liquid. In cooking, this is done by boiling the liquid rapidly in order to speed the evaporation process. While some liquid evaporates, the remaining liquid thickens and the flavor intensifies. Reduction is a great way to make a flavorful sauce for meats or vegetables. Recipes asking for reduction involve a liquid and most often that liquid contains either broth, stock, wine or vinegar.
When a recipe asks for reduction of the liquid, the amount of reduction is either specified as reducing the liquid by a general amount – usually one-third or on-half. Or, the recipe may say to keep boiling until the liquid has reached a specific volume, such as 1/2 cup. The second way is more difficult to measure since you are generally boiling in a pan without measurement markings.
Speaking of the pan, your pan size greatly affects the time it will take to reduce your liquid. Since a larger pan has a greater surface area, the evaporation process will be much quicker than in a smaller pan. For best results, be sure to use the pan size that is recommended in your recipe.