Simmering broth for an extended period (several hours) results in a richer, more concentrated flavor and a fuller body due to the breakdown of collagen and extraction of more flavor compounds. A shorter simmer yields a lighter, less intense broth.
The flavor of broth is significantly impacted by the simmering time. When you simmer broth for a longer duration, several key processes occur:
Collagen Breakdown: Bones contain collagen, which breaks down into gelatin during simmering. Gelatin adds body and a silky mouthfeel to the broth. Longer simmering allows for more complete collagen breakdown, resulting in a richer texture.
Flavor Extraction: Extended simmering allows for a more thorough extraction of flavors from bones, meat, vegetables, and herbs. The longer the ingredients are in the hot water, the more flavor compounds are released.
Concentration: As the broth simmers, water evaporates, concentrating the flavors. This is especially noticeable with longer simmering times, leading to a more intense and robust flavor profile.
Development of Deeper Flavors: Longer simmering can also lead to the development of more complex and nuanced flavors through Maillard reaction-like processes, even though the temperature isn't high enough for a true Maillard reaction. These subtle changes contribute to a deeper, more savory taste.
Conversely, a shorter simmering time will result in a broth that is lighter in flavor and body. While still flavorful, it won't have the same depth or richness as a long-simmered broth.
Avoid boiling broth vigorously, especially for extended periods. A gentle simmer is key to preventing the broth from becoming cloudy and developing bitter flavors from over-extracted impurities.