What you see
When ground coffee is first wetted, bubbles often rise and the coffee bed expands. Some gas escapes from the roasted coffee. In pour-over brewing, this first phase is often called blooming. How visible it is says little on its own about bean quality or the eventual taste.
What the pause is for
During pre-wetting, all the grounds should come into contact with water. Dry pockets inside a small mound hinder an even start. A brief pause also gives you a clear point in the process: wet first, then continue the main pour.
How much the coffee blooms depends on factors including roast, age, grind and storage. Few bubbles therefore do not automatically mean poor coffee. Conversely, lots of foam does not prove the cup will be balanced.
A practical introduction
For the 15-gram V 60 recipe, you can use around 45 grams of water to wet the grounds and wait around 30 to 45 seconds. This guidance comes from Hario's instructions. The blooming water is part of your total 250 grams of brewing water, not an extra amount on top.
If you instead plan 300 grams of total water, subtract the first portion from that. This small calculation prevents your recipe from becoming thinner unnoticed.
How to work calmly
- Loosely level the dry coffee bed. Avoid a tall mound in the middle.
- Pour the first weighed portion so the entire bed is wetted.
- Check for visible dry patches. A small, gentle movement can help; vigorous stirring is unnecessary.
- Wait for your chosen period, then continue with the remaining pour.
If something is not right
If dry clumps remain, the initial amount of water may be too small or the stream unevenly distributed. More time alone will not wet a dry island. Correct the distribution first. If the filter later backs up noticeably, consider agitation and fine particles as well as grind size.
A comparison of your own
Brew the same coffee twice with an identical recipe. On the first run, simply observe; on the second, pay particular attention to wetting everything gently and completely. Keep the waiting time the same. This tests a specific technique, rather than trying to guess the effect of blooming from completely different recipes.
Do not apply to every method
A closed immersion dripper or French press already provides a shared bath of water. You do not need to copy the same pause used in pour-over brewing. Portafilter machines have pre-infusion functions with pressure and timing sequences specific to the machine. A similar aim does not make the methods identical.