Do You Speak Roaster? A Beginner's Guide to Coffee Roasting Jargon
Charge. Rate of Rise. First Crack. Development. Drop.
Walk into a conversation between two coffee roasters and you might start wondering whether they're actually talking about coffee.
Like most industries, coffee roasting has developed a language of its own.
For experienced roasters, these words become second nature. But when you're just getting started, roasting jargon can make something that's already complex feel even more intimidating.
It doesn't need to be.
So, welcome to your first lesson in speaking “Roaster”.
Here are five terms you'll hear all the time and what they actually mean.
1. Charge
No, we're not talking about your electricity bill.
Charge refers to the beginning of the roast, when green coffee is introduced into the roasting chamber.
You'll also hear roasters talk about charge temperature, which refers to the temperature at or around the point when the coffee is loaded into the roast chamber.
However, in an AMR we are different, we do not preheat our roast chamber before loading our beans into it as drum roasters do.
This starting point forms part of the roaster's overall approach to how energy is applied to the coffee from the beginning of the roast.
So when you hear:
"What's your charge?"
Don't reach for your wallet.
We're talking coffee.
2. Rate of Rise or RoR
This one sounds much more complicated than it needs to.
Rate of Rise, usually shortened to RoR, tells us how quickly the measured temperature of the coffee is changing over a period of time.
In an AMR our probe measures the bean temperature every half a second and then informs us of how many degrees in Fahrenheit or Celsius the bean temperature is increasing every 30 seconds.
Think about driving a car.
Your temperature reading is a little like knowing where you are.
Your Rate of Rise helps tell you how quickly you're moving.
Two roasts could be at a similar temperature at a particular moment but be heading there at very different rates.
That's why RoR can be such a useful piece of information when understanding how a roast is progressing.
3. First Crack
Here's one you can actually hear.
As coffee absorbs heat during roasting, moisture turns into steam, gases develop and pressure builds inside the beans.
Eventually, physical changes inside the bean cause its structure to fracture and release pressure.
The result?
Crack. Pop. Crack.
That's first crack.
For the roaster, it's an important sensory marker and signals that the coffee is entering another significant stage of the roast.
The advantage of the AMR Open Roast Chamber is that is makes the first crack sound highly audible to the roaster to identify.
We've written a whole article about the science behind first crack, because there's much more happening inside those little beans than the sound suggests.
4. Development
Once first crack begins, we enter what roasters commonly call the development phase.
This is an important part of the roast where the coffee continues to develop as we work towards our desired end point.
You'll often hear people talking about development time or development time ratio when discussing roast profiles.
But don't fall into the trap of thinking there's one magical development percentage that works for every coffee.
Roasting is about understanding the coffee in front of you and working towards the flavour profile you're trying to achieve.
Numbers can guide us.
But with the AMR’s open roast chamber we have the advantage of using sight, sound and smell as well, it’s all there right in front of you.
5. Drop
Finally, we have perhaps the easiest roasting term of them all.
Drop.
This is when the roast reaches its desired end point and the coffee is released or "dropped" from the roasting chamber into the cooling system.
But just because we have engaged our cooling process in our roasting chamber with our water dousing system doesn't mean our job is finished.
Roasted coffee contains a significant amount of thermal energy, so effective water dousing is important to stop the roasting process quickly but then we drop the beans into the cooling tray to get the beans to room temperature as quick as possible.
Then, after all that careful roasting…
it's time to see what we've created.
Congratulations. You now speak a little Roaster.
Coffee roasting can be incredibly technical.
There are roast curves, temperatures, airflow, energy changes, chemical reactions and countless variables to understand.
But you don't have to learn everything at once.
Start with the language.
Charge.
Rate of Rise.
First Crack.
Development.
Drop.
Five terms. One roast.
And suddenly, that conversation happening beside the coffee roaster makes a little more sense.
At Air-Motion Roasters, we're passionate about making roasting knowledge accessible, whether you've been roasting for years, you've just bought your first roaster, or you're simply curious about what happens between a green coffee bean and the coffee in your cup.
So, consider this Do You Speak Roaster? Lesson One.
There are plenty more roasting terms where those came from.
Happy Roasting !
Written by: Julian Platt
Comments