Proper pour over technique is a matter of great debate and a fair amount of science. In fact, there should be a college course on pour over brewing technique! There would certainly be enough material to justify a full semester, and entire generations could be saved from wasted years of drinking terrible coffee.
Obviously, one blog post is not enough space to nail the mysteries of the universe, much less to fully discuss proper pour over technique. To be honest, I have not reached 100% pour over technique mastery, even though I can consistently produce a wonderful cup of coffee awesomeness.
We can, however, get the basics down well enough to make great coffee and troubleshoot most problems. This post applies to pour over equipment such as the Hario V60, a Melitta, or the Able Kone.
Ratio – Assuming that you are starting with good quality, freshly roasted coffee (let’s face it, what is the point of brewing garbage well?), you need to have the right amount of coffee for the amount of water you are going to use. Too much coffee will lead to several problems such as over-extraction of the front-end coffee solids, or a slow brew which takes too long and becomes bitter. Too little coffee can lead to a weak, under-extracted brew that is completed too fast.
The perfect ratio depends on the origin and quality of the coffee, the roast level, and grind size. In general, you should be in the 16:1 range. That means that for every gram of coffee, you should use 14 grams of water at just over 200 degrees Fahrenheit. After you try a few brews at exactly that ratio, you can tweak the ratio up or down a bit. If you find yourself more than just a little off that ratio, something else needs to be adjusted.
Grind – The proper grind size for pour over is somewhere around 600 microns, or about a 0.6 mm diameter particle size. Of course, few people take a ruler to their coffee, so shoot for particles similar to pre-ground coffee that you have purchased from a reputable shop.
There are several ways to tell if your grind size is off. Perhaps the best is brew time.
Time – Pour over brewing should take approximately 3-3 ½. In that time, the water will dissolve a very desirable flavor profile, but leave most of the bitter components safely lock in the grinds.
If your brew time is coming in under 3 minutes, your grind size may be too large for your brew method. If the time drags on well over 4 minutes, the grind size may be too fine, or the grind size may be inconsistent and include a lot of fine grinds along with the properly sized grinds. The fines clog up the pores in the filter, slowing the brew.
These high level tips should be enough to produce some great coffee, or start you on the path to a lifetime of tinkering and tweaking your equipment and technique in search of the perfect cup.