What does the term "bloom" refer to in coffee brewing?

The term "bloom" in coffee brewing specifically refers to the initial release of carbon dioxide from coffee grounds. When freshly ground coffee is steeped in water, it releases trapped carbon dioxide, which can create bubbles and a frothy appearance on the surface. This step is crucial for achieving optimal extraction, as it allows the coffee to degas before brewing truly begins. By allowing the gases to escape, the water can better interact with the coffee grounds, leading to a more balanced and flavorful cup. The bloom typically occurs during the first few moments of the brewing process, especially in methods like pour-over, where water is initially added to the grounds before a full immersion takes place. Understanding the blooming process helps baristas and coffee enthusiasts enhance the quality of the brew.