Is there a standard for establishing a roast profile?
Any roaster will tell you that every coffee is different. When it comes to different origins, varieties, processing methods or bean densities , there are many factors that influence how you roast coffee. Furthermore, it is the roaster’s responsibility to highlight the best characteristics of each coffee, especially those that make it more unique. Therefore, roasters must develop different roast profiles to achieve the best results.
Therefore, it is worth asking whether there is a universal approach to roast profile that coffee professionals can follow – and then adjust according to each coffee? Or is it better to take a different approach for each grain? I spoke to Marcus Young, Executive Vice President of Coffee at goodboybob , and Fabio Ferreira, partner at Notes Coffee , to find out more.
What is a roast profile?
In the coffee industry, we often talk about light, medium and dark roast profiles – but what do they really mean? Sweet Maria’s defines a roast profile as “ what happened during the roast and what adjustments were made to affect the result .” Essentially, it is a set of data collected during roasting. This data is displayed on a graph (or roasting curve ) so it can be replicated – similar to a cooking recipe.
We can then define the roast profile as the process of manipulating variables, such as time and temperature, to obtain a good balance of acidity, sweetness, bitterness and texture for a specific coffee. Marcus is the Executive Vice President of Coffee at goodboybob, a Golden Bean award-winning specialty coffee roaster in California, USA. He says a big part of learning how to develop roast profiles is tasting lots of different coffees. “To be a great roaster, you first need to be a great cupper” he says.
Cupping is an industry practice carried out by producers, green coffee buyers and roasters around the world to taste coffee. It follows a standard set of preparation protocols, which Q graders use to evaluate and score sensory profiles and quality . Regularly tasting a variety of coffees – including different origins, altitudes, processing methods and varieties – means roasters can better understand the wide range of coffee flavors. In turn, the process of developing and customizing roasting profiles becomes easier.
Why is he so important?
As we’ve established, every coffee is different. For example, a coffee grown in a humid climate at a lower elevation will react differently when roasted compared to another coffee grown at a higher elevation in drier environmental conditions. But climate and altitude are just two factors among many that affect the roast profile.
Take origin, for example. With most Kenyan coffees having a much brighter and more prominent acidity than coffees grown in other countries, this needs to be taken into account when developing a roast profile. Likewise, you also need to roast washed coffees differently than natural, honey , and experimentally processed coffees. Considering this, there is no one-size-fits-all approach to creating roast profiles. But what roasters can do is follow the general steps and guidelines to find the ideal profile for a given coffee.
How to establishing a roast profile?
For more experienced roasters, it is often easier to develop an initial roast profile for a coffee they have never purchased before. Fabio founded the British roasting company Notes Coffee in 2008, together with Robert Robinson. He says when he buys new coffee, he looks at previous roast profiles to find a good starting point. “I use this roast profile as my baseline so that I don’t blindly roast new coffee.”
This obviously helps increase the chances of developing a good roast profile the first time – and then adjusting to improve results. However, newer roasters are unlikely to have as large a catalog of roast profiles as more experienced ones. In turn, they need to consider various attributes of the coffee and build a roast profile from there.
To help with the process, Fábio and Marcus recommend buying coffee from a previous harvest from your supplier. Less experienced roasters can then use this cheaper coffee to play with the roast profile and better understand how different variables affect the overall sensory profile.
What are the most important factors to consider?
There are, of course, many crucial variables to take into consideration when developing a roast profile. “Bean density is an essential factor in understanding how I can roast a specific coffee,” says Marcus. For example, you may need to roast denser coffee at a higher temperature, while less dense coffee generally requires a lower drop temperature and a gentler approach.
“Similarly, the processing method can also tell me how much heat to apply,” he adds. “A washed coffee, I would roast for a little longer, while a natural coffee, I would reduce the total roasting time to show more of its flavors.” In addition to grain density and processing method, other variables are also essential to keep in mind:
- variety (which affects grain size – another important factor);
- origin;
- moisture content (which should be between 8% and 12.5% for green coffee ).
Understanding what causes roast profiles to change
Although green coffee is a stable product, it ages over time, usually about a year after harvest . That’s why roasters need to be aware of how this coffee will change in the coming months. As beans age, they begin to lose acidity and sweetness. This means that to avoid unwanted flavors, roasters need to create roast profiles accordingly.
“With older green coffee, I tend to roast it a little longer, which gives it more time to develop the sugars and flavor compounds,” says Marcus. “For example, if it was a ten-minute roast when the coffee was fresh, I would increase the total roast time to 10.5 or 11 minutes.”
Both green and roasted coffee must be stored in ideal conditions to preserve freshness and quality for as long as possible. Variables like temperature, humidity levels, and exposure to light and oxygen play a big role in this. Looking specifically at temperature, significant fluctuations will cause green coffee to age much more quickly, which affects how the coffee will roast. “Even the climate will influence your roast profile”, says Fábio.
He describes a time when he developed a roast profile for a specific coffee that should have produced good results, but his curve was “completely off the charts.” “It was very cold that day,” he adds, emphasizing that roasters must take into account weather conditions on batch production days and how they can affect the roasting process.
Maintain variable consistency
There are certainly many other factors that can influence a roast profile. However, some of them are more related to technique than how coffee is changing over time. The batch size, for example. If you roast with a different amount of coffee each time, you will inevitably receive different results with each batch. This is because batch size affects airflow in the roaster, which interferes with heat distribution in the machine.
Likewise, if you roast the same coffee in two different machines, the results will likely be noticeably different. As a general rule, keep variables like batch size and machine type as consistent as possible. It is much easier to identify other key variables that need to be changed to achieve the best possible roast profile.
Tips and advice for approaching roast profile development
It takes a lot of practice to create an ideal roast profile for a particular coffee. However, the process should not be intimidating. Finally, you always need to consider the flavor of the coffee – and develop a profile that best highlights these characteristics. “The reality is that there are many ways to roast great coffee, and people should be open-minded to good surprises” says Marcus.
Fábio, in turn, recommends that roasters not get too fixated on the issue of the roasting curve. “Sometimes it’s very easy to not look at the numbers and how the roast curve has developed, or take into consideration the coffee you’re using. You might have a nice roast curve, but the coffee might not taste as good as expected,” he says.
Tasting different coffees
As mentioned earlier, one of the most effective ways to improve roasting skills is to try as many different coffees as possible. “For those who start roasting, study the cup of coffee. It’s easy to train new roasters to manage machines and follow profiles, but you need to know how to taste coffee. And sometimes that’s the hardest part of the job. A good roaster needs to know how to improve the acidity and sweetness of the coffee – it all comes down to tasting”, concludes Fábio.
Is there a universal way to approach roast profile? Well, yes and no. With each coffee being unique – and changing over time – roasters need to take these differences into account to get the best results.
One thing roasters can always do to improve the consistency of their roast profiles, however, is to taste lots of different coffees regularly. This way, they can better understand the variety of coffee flavors – and how to highlight them as much as possible.
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