Preparing Rich, Thick Soups and Sauces
Many techniques and ingredients are used to thicken soups. While many classic soup recipes call for thickening using roux, today there are a variety of ways to add body and tighten up a soup that is too watery. Eggs, vegetables, and starches all offer options to adjust the consistency of a soup. The ingredients of the soup usually dictate which thickening is used for the desired end result.
Eggs: A Volatile Thickener
The least common and most volatile soup thickener is eggs. Eggs are used as a liaison in many cream sauces and desserts and can also be used to thicken a soup. Regardless of its use, the technique is always the same. The eggs (often just the yolks) are placed in a bowl and whisked together with a small amount of the hot liquid to temper the eggs. Cold eggs scramble if added directly to the soup without tempering. The warmed eggs are then added back to the soup and slowly warmed until the soup thickens. This usually takes only a few minutes. The soup must be immediately removed from the heat and/or transferred into another container so that it does not continue to cook. These soups need to be served immediately after preparation because the eggs do not hold up well and if kept warm or reheated run a good risk of breaking down.
Thicken with Robust Starches
Soups are often thickened with cooked potatoes, beans, or other starchy vegetables, which are added just before the soup is finished. If it is to be served as a puree, the vegetables can be added to the entire batch of soup and everything pureed together. If it is not going to be a straight puree, then a portion of the finished soup can be blended as is, or with the addition of a starchy vegetable, and then stirred back into the original pot of soup. Either way the flavor is not being diluted and if anything becoming more intensified as the puree is incorporated.
Thickening with Grain: Flour, Rice and More�
Flour, cornstarch, rice, and bread are also good thickeners. Flour and cornstarch are a little less desirable because they sometimes impart a grainy consistency and undesirable flavor. In a pinch, however, they are good last minute solutions. Rice and bread are often used in the same way as vegetables. With rice you also run the risk of graininess if it is not properly cooked or pureed. Bread offers one of the best thickening options. A simple white bread, without crust or any seeds can be added to the soup once it is completed, allowed to absorb the liquid for a few minutes, and then pureed. The end result is a luscious, silky texture.