Roasting ingredients is not strictly necessary for making broth, but it significantly enhances the flavor. While roasting is more commonly associated with stock, it can be beneficial for broth as well.
The primary difference between broth and stock lies in their ingredients and intended use. Broth is typically made with meat and vegetables, sometimes including bones, and is often seasoned. Stock, on the other hand, is traditionally made primarily with bones and aromatics, and is usually unseasoned or lightly seasoned.Roasting bones and vegetables before making stock or broth caramelizes their natural sugars, creating a richer, deeper, and more complex flavor profile. This process, known as the Maillard reaction, develops hundreds of flavor compounds that contribute to the overall taste.When making stock, roasting bones is a common practice to extract maximum flavor and collagen, which contributes to a richer mouthfeel. However, roasting vegetables like onions, carrots, and celery can also significantly improve the flavor of both stock and broth.If you choose not to roast, you can still make a perfectly acceptable broth. The flavor will be lighter and fresher, but it may lack the depth and complexity achieved through roasting. Unroasted ingredients will impart a cleaner, more delicate flavor.
For a richer, darker broth or stock, roast your ingredients until they are deeply browned but not burnt. Burnt ingredients will impart a bitter taste to your final product.