Pour-over wants a medium grind, roughly like coarse sand. The exact setting depends on your grinder, the brewer, the paper and how much coffee you brew, so the most useful guide is the drawdown time, which is how long the water takes to drain through the bed.
Start here
For a single V60 of 15 g coffee to 250 g water, aim for a total brew time around 2:30 to 3:30. Find your grinder's typical pour-over range in the grind size chart and start in the middle.
Read the drawdown
- Drains too fast and tastes sour or thin: grind finer.
- Drains too slowly, stalls, or tastes bitter and dry: grind coarser.
- Bigger batches drain slower, so grind a little coarser as the dose goes up.
Paper changes the grind
Filter papers flow at very different speeds. A fast paper lets you grind finer for more sweetness, while a slow one needs a coarser grind to avoid stalling. If you switch papers, expect to move the grind, and keep separate notes for each one.
Keep a setting per paper
Treat each paper as its own setting. Write down the grind that works with each one, so switching papers doesn't mean losing the setting you'd already found.
Find your grinder's typical settings in the grind size chart.
Notchbook is a free app that remembers the grind setting that worked for each coffee, grinder, brew method and filter paper, and keeps a journal of every brew. Get it free on Google Play. The iPhone app is coming soon. More about Notchbook.