What water temperature and pour speed are best for pour-over method? I had a recent discussion with a friend of mine, which is the right method to brew the coffee for pour-over.

I read that it's best to pour in hot (but not boiling) water into the filter and moisten the coffee powder. After that I should pour in the water until it is round about 1 cm over the coffee powder. After that I should let it flow out and fill the water up until it's reached the 1 cm mark over the powder.

His method is a bit different. He just pours the hot (even if it's still boiling) water into the filter. He briefly moistens the coffee and then lets the rest of the water pour into the filter until his water can is empty. He only pauses from pouring if it reaches the top of the filter. 

I said that his method isn't good, as the water will flow faster through the filter and the coffee won't be as aromatic as it would be with my method.

The brewing process I'm using is using the hand-filter with the Hario V60.

Which method is better? Does it matter how fast to pour the water in? Does it matter if the water is just hot or still boiling?
You're highlighting two differences between the two methods:


temperature of the water, and
rate of pouring the water (equivalently, how "full of water" is the cone).


Short story: Use water just off the boil (about 96°C / 205°F). I prefer your "slower" pour method over your friend's... read on for why.

Longer story:
Keeping all other factors identical, here's my take on each. I aggregate information from my own experience and from several other sites (including Blue Bottle and Stumptown and Serious Eats and Coffee Geek).

Temperature. Most agree that water for pour-over should be just off the boil, but exact temperature is both difficult to measure and to maintain. Exact recommendations differ, but most (including the 4 above) are approximately in the range of 93-97°C / 200-207°F. At this temperature, you extract the best balance of the "right stuff" from the beans. Much hotter or colder than this and it will have an "off" taste, such as more bitter. For example, try brewing coffee at 80°C / 175°F and see how it tastes compared to coffee brewed with 96°C / 205°F water.

With my technique and equipment, anyway, it would be essentially impossible for me to measure or maintain a temperature this accurately. Removed from the heat, the kettle itself will immediately start to cool; the water will cool between the pour spout and when it hits the grounds in the cone; the water will cool more when sitting on the grounds. For this reason, I take water from a boiling kettle and begin to pour at my leisure. It might be a few degrees too hot at first, but it will probably finish a few degrees too cool.

Rate of pouring the water. This seems to have more debate, e.g., on the 4 sites I listed above. Some pour only enough water at a time to have water just covering the grounds (like you and Blue Bottle), and some pour all the way up to the top of the cone (like your friend and Stumptown) -- however, a disadvantage of this all-at-once method is that some of the coffee will get pinned to the side of the cone for the final "drainage" and will not spend as much time in contact with the water; therefore some of your friend's coffee grounds will be underextracted. I do something of a hybrid: pour at such a rate as to keep the output at a steady rate. The dripping rate will decrease as the filter gets somewhat clogged with grounds, so I keep very slowly raising the water level in the cone (just exceeding the rate of output); I find this produces the best result. Other ideas are to stir (as Coffee Geek suggests) or pour in batches (as Serious Eats suggests).

All that said, other factors (e.g., the quality and freshness of beans) are overwhelmingly more significant than the manner of pouring.

You may also want to consider rinsing your filter, and see more about wetting the grounds for coffee bloom.