Blooming – Growth – It is the swelling or bubbling (CO2) that occurs when boiling water comes into contact with the coffee for the first time (usually only when making filter coffee, Pour-Over). Blooming is generally thought of as a stage or two in the brewing process. To be more specific, you’d start by pouring in just enough water to soak the coffee, then wait for It to finish – that is, for the water to stop bubbling – before slowly running in the remaining water to extract.
More information about the coffee brewing process can be found here (Blooming)
It is used in brewing processes to liberate the remaining carbon dioxide from the coffee bean structure, allowing the water to reach deep inside the bean structure and eliminate contaminants. coffee’s most important flavor