What Remains
Now that we have all of our gear, we’re finally ready to brew. So what’s our secret? Consistency. You know better than anyone what tastes good to you,
and we’re not interested in telling you what tastes good or bad. You have the tools to adjust the flavor profile of your coffee by changing the dripper,
the filter, the brew ratio, the water quality, and the grind size. The remaining variables to control are water temperature and flow rate.
It’s a little known fact that OneNinetySeven is a reference to a brewing temperature, and though this is a perfectly reasonable temperature to brew at, it is by no
means the only way to do it. Your water temperature is going to interact with your grinder particle size distribution to produce certain flavors. Not
everything inside of a coffee bean tastes good, so using the hottest possible water is generally not the best idea. On the flip side, cold water will
extract the coffee more slowly, so a pour-over made with cool water will tend to be under-extracted and super sour. This is why the SCA recommends a brewing
temperature between 195F and 205F, but there really isn’t a wrong answer here. We tend to use cooler water on more developed coffees and finer grinds as they
extract more readily. Just play around in the range until you find something you’re happy with.
The importance of flow rate is perhaps a bit less well understood, though we would argue it’s really more about water temperature stability. Just as different
grind sizes will produce different flavors, different flow rates will change the temperature of the coffee as it brews, altering the speed of extraction, thereby
changing the flavor in the cup. This is where consistency comes back into play. During the second pour, after our pre-wetting bloom period, we like to pour the water
into the dripper in alternating concentric circles at about the same rate as the water is draining out into our vessel. This holds the coffee at a more consistent
temperature during the extraction process, and tends to produce a more balanced cup. The concentric circle bit is an effort to produce an even wetting of the coffee
grounds, which will result in a flat coffee bed at the end of extraction. If you pour too much water into one part of the brewer, that area will tend to over-extract,
whereas the rest of the coffee in the brewer will tend to under-extract. This leads to that dreaded combination of bitter and sour all at once. You should hope to find
a flat coffee bed in your dripper at the end of extraction - no peaks or valleys.