Every pour-over is four phases, in the same order, every time. Knowing what each phase does is the difference between following a recipe and reading what's happening in front of you.
The four phases
Bloom (0:00 – 0:45). Degassing. Small pour, then wait.
First pour (0:45 – 1:30). Body building. Roughly 60% of the total water goes here. Most of the soluble flavor comes out during this phase.
Second pour (1:30 – 2:30). Top up. The remaining water to hit the target weight. Pour gentler — agitating the bed late stalls the drawdown.
Drawdown (2:30 – 3:30). Gravity finishes. No more pouring. Water percolates through what's left in the bed. Aim for a total brew time of 2:30 to 4:00.
Reading the drawdown
If water is still 30 seconds away from finishing when you expected it done, your grind was too fine.
If it drained 15 seconds early, too coarse.
You don't have to fix it mid-brew. You taste the cup, you adjust the grinder one notch, you remember.