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 gas when hot water first comes into contact with freshly ground coffee. During the roasting process, coffee beans develop carbon dioxide, which remains in the beans until they are ground. When water is poured over the grounds, this gas expands and escapes, causing a bubbling effect. This step is crucial because it allows for better extraction of flavors in the brewing process, leading to a more aromatic and flavorful cup of coffee.

Understanding the concept of bloom is essential for brewers who want to optimize their coffee-making technique and enhance the taste profile of their beverages. The other options pertain to different aspects of brewing, such as the final stages or processes not directly linked to the initial interaction between water and coffee grounds.