The terms soup and stew can get confusing and some dishes are referred to as either, depending on the cook. There are some dishes that can be made as a soup or a stew, such as wonton soup, gumbo stew, miso soup, and Brunswick stew. While the two types of foods may seem similar, there are some ways to differentiate between them. First, most soups are thin compared to thick stews; second, stews are almost always served warm while some soups can be served hot or cold; and third, stews are typically slow-cooked as opposed to soups that can be prepared and heated fairly quickly, depending on the recipe.
Thick or Thin
One of the most important differences between soup and stew is the thickness — when compared to one another, soups are considered thin while stews are thought to be thick. A soup is basically any combination of pasta, meat, or vegetables cooked in liquid. Most soups are "thin," as the ingredients typically include several cups of water or some type of broth; it is also possible to make soups using milk or even fruit juices. Soup is best served in a bowl or deep plate, since most of it is basically liquid.
Stews can be simply described as "hearty soups," often with meats and vegetables, including potatoes. When comparing soup and stew, the latter is usually considered a main dish and soup a side dish, because stew is typically more filling than soup. The liquid in a stew is minimal, and any liquid is usually thickened to the point of being more of a gravy than a broth, making stew thicker than soup. Some thickening methods include blending some of the vegetables and adding the puree to the stew, adding an equal mixture of flour and water to act as a thickening agent, or gently boiling the stew to reduce the liquid.
Temperature
Another difference between soup and stew is the temperature at which it is served. Most soups can be eaten as either hot or cold dishes, can be cooked or uncooked, and some are even considered a dessert such as fruit soup. Stews, on the other hand, are almost always consumed hot. This is partly due to preference and partly due to the slow-cooking method of stew that usually leaves the stew warm after it is cooked and served.
Cooking Time
The time it takes to prepare and cook soup and stew is another way the two dishes are different; soup is generally quicker to make, while stew requires a longer cooking time. Part of the characteristic flavor of a stew stems from the slow cooking process, which allows the natural flavorings of the foods being simmered stay in the stew; while this process does take longer, it is thought to make the stew more flavorful. Sometimes a thickening agent is added to make the stew more gravy-like, which can take several minutes to actually thicken, adding to the length of the cooking time. Soup, on the other hand, usually relies on added flavorings, such as condiments and garnishes that do not require slow-cooking, and can be put together quickly to be heated and consumed later.