The way a cup of coffee is brewed is essential for the way it is going to taste. There is an ocean of different coffee brewing methods all with each their pros and cons. Generally you split them into two groups: Infusion/Immersion and Percolation. Pour-over is a subcategory of Percolation which is characterized by that the water is either poured or pressed through the grounded beans.
Pour-over is becoming the strongest brewing trend in the world. The method is similar to the nostalgic old school manual filter coffee from before the use of conventional automatic coffee machines and falls under the category “Drip-Coffee”.
The setup still requires a filter, grounded coffee beans, a funnel and a pot but in pour-over coffee the focus is especially on all the variables that define the taste profile:
Whereas the other the previously mentioned parameters speak for themselves, blooming is to many an unknown step in the brewing process. This is in spite of it being a rather important part of the Pour-Over method.
Blooming is the first wetting of the ground beans which happens before the primary water is poured over the beans. During the blooming step the beans are able to degas which makes the coffee rise and bubble. A fresh batch of ground coffee beans can be recognized by the increased amount of escaping gas.
The gasses that are released during blooming allow for a better extraction of the flavours and aromas that are unique for all beans.
Another obvious advantage to blooming is that the water is utilized better. If you simply pour all the water on the beans continuously right away a larger part of it will have run through before all the ground beans have been in contact with water. This results in some beans being over extracted and others under extracted and essentially a more bitter cup of coffee covering the unique aromas.Lastly blooming ensures that the minimum amount of CO2 is dissolved in the coffee as it is released in the gas, again making the coffee less bitter.