The Debat About Roast Levels: Why Communicating Them Is So Difficult

When we started out Kultivar Coffee we started writing a comparison guide for Saka Caffé called "Saka Espresso Comparison Guide: Find Your Perfect Espresso" to give more information and a recommendation for people as a starting point. A rough draft you might say because your palette may not align with ours, maybe you have a higher tolerance for bitterness and lesser tolerance for fruit forward flavours in your cup. And taste is very subjective.

Confusion about roastlevels
One thing that we wanted to make clear in that guide was what roastlevel you could expect inside a bag of Saka Espresso. Often the first thing you do when picking up a bag is checking the roastlevel, the tasting notes and hopefully check if there is a roastdate on the bag too! In the world of coffee, few topics spark as much confusion as roast levels. Everyone—from baristas to roasters to home brewers—talks about light, medium, or dark roasts, yet no one seems to agree on what those terms actually mean. Quite often Italian espresso is associated being a dark roast, strong cup of coffee. We decided to dig deeper into this matter to find out if Saka Espresso, a Neopolitan coffee, is a dark roast coffee and found out...we were wrong.

How to objectively classify coffee roast levels
The friendly folks at Solace Coffee were kind enough to lend us a DiFluid Omix Plus green coffee & roast color analyzer which makes objective color measurements possible. It uses the so called Agtron scale, which is a standardized color measurement system for roasted coffee, ranging from 25 (very dark) to 95 (very light). Roasters often use it for quality control and consistency. The Specialty Coffee Association (SCA) has adopted this system to define its widely recognized coffee roast classification standards. By precisely quantifying roast levels through Agtron values.

Results of our samples
We took samples from coffee with the same roastdate, grinded it with a Commandante C40 on the same grindsetting and measured it (see all the measurements below) and to our surprise non of the coffee classified as a dark roast. While these metrics give an objective measurement, they don't tell the whole story. Why? Because coffee roasting is both a science and an art. While a green coffee & roast color analyzer attempt to quantify roast level, flavor perception depends on variables far beyond color—origin, processing method, roast development time, and even the drinker’s sensory experience.

Color ≠ taste
Roasting coffee transforms green beans into the aromatic brown ones we love. Light roasts preserve acidity and fruity notes. Medium roasts balance sweetness and brightness. Dark roasts emphasize bitterness and body. Yet, two beans roasted to the same Agtron number may taste completely different depending on roast curve, airflow, and origin. You might say that Agtron numbers are completely useless. However it is a standardized consistent metric to compare roast degrees without any personal bias, it can be used to get a general understanding of the coffee and color seemed the simplest way to do so.

Where does that leave us?
Roasts come in many colours, and we are not going to dictate what’s best. Also we don't expect you to bring a roast color analyzer to every coffee debate ;-). When discussing roastlevels it is important to try and describe what coffee you drink (e.g. the name of the roaster), what flavor descriptors you are getting and what your personal take is on coffee you generaly prefer. You might say that you think that the coffee is a light roast coffee while another person could say that it's medium to their knowledge. Everybody's scale/taste is "calibrated" differently, another way to look at it is by telling somebody that you find a coffee too light for you, in your own personal (median/medium) zone, and “dark” as too dark for you. It doesn’t matter what kind of roast you are into but it can give another person a perspective whether they are aligned with your preferences and hopefully find a common ground (phun intended :-)