Skip to main content

09 Sep 2020 | Cheryl Ng

Turn Up the Heat: Roasting Coffee with Rob Hoos

For all of us in this together, all we can do is support each other in coffee and keep roasting the quality, specialty coffee that we love. For everyone out there who is #stillroasting, here are a few words from Rob Hoos, friend of Bettr Barista and one of the most lauded roastmasters of the land.

The aroma of roasted coffee is irresistible. Even for those who don’t drink coffee, the smell of slow roasting beans wafting out of coffeehouses is enough to stop them in their tracks and appreciate it.

Hundreds of chemical reactions occur when coffee is roasted from a green bean to a variety of roast stages - you might recognise roasts like French, Nordic, Italian, Turksih, American, full city, cinnamon, Vienna, to name a few. The science, patience, and meticulous precision that roasting requires can take years to perfect. Roastmaster Rob Hoos teaches exactly that.

When Rob became interested in roasting, he noticed a lack of information available, and his career has since brought forth the answers to some of the questions he had. Experimental, curious, and methodical, Rob was instrumental in devising roasting curriculum for the Specialty Coffee Association. His years of experience contributed to the first book of its kind - Modulating the Flavor Profile of Coffee: One Roaster’s Manifesto - in roasting, which is also translated into Simplified Chinese and Spanish. Once a year, Bettr Barista hosts Rob Hoos in Singapore all the way from Portland, OR to teach a professional roasting course. 

During Rob’s last visit, we got to learn a few tips and tricks from Rob about roasting and hear his story.


Let’s start from the beginning. What drew you into coffee?

Rob: I’d say that the flavor of coffee is what initially drew me in. I grew up drinking coffee, albeit poor quality coffee, with my parents from the age of 5. As I got older, especially in late high-school and early college, my coffee consumption increased as it usually does. Once when I was attending church with my mother, I tried helping out by brewing coffee for the morning, and I ended up being banned from brewing it again. It turns out that you are not supposed to fill the coffee filter to the top. They even put my picture up with a red x over my face above the coffee brewing station. But one of my friends at the time made an interesting suggestion… it was around the same time when "being a foodie" was starting to become a thing where I lived. 

My friend Zach looked at me and said... "Rob, lots of people are 'foodies' these days... what if coffee was our thing?" I had always enjoyed the taste of coffee and so it seemed like a fun, and worthwhile adventure. In late high school and early college, I spent a lot of time with Zach, drinking coffee (usually we’d brew two french presses side by side) and watching terrible sci-fi movies, and at some point we began to be able to tell the differences in flavors. 

In college, I was the guy who had a coffee brewer, grinder, and small steam powered espresso machine in my dorm room. I had the habit of making coffee drinks for anyone in our dormitory who was interested. During my sophomore year of college, I had the opportunity to work as a barista on campus and I realized that I loved working in the field that was originally my hobby... I actually preferred being a barista to my studies.

I worked full time as a barista after an internship related to my degree and then again during my Master’s program. During that time I first had the opportunity to roast with a small 5kg roaster at a cafe in Cincinnati. I had already been experimenting with home roasting, and as I transitioned onto the large roaster it became a very strong passion for me. I was, however, frustrated at the lack of information available on coffee roasting. Baristas had always been very open about sharing information, but roasters had (especially during those days) been very secretive. Over time, I saved money and bought a 1kg roaster to start experimenting. I started learning how to design roast profiles for flavor instead of just following established profiles at work. This exploration of flavor differences due to roasting became a bit of an obsession... after all, that’s what got me into coffee in the first place.

Since then, how did you carve out your career in roasting?

Rob: I was lucky, mostly. I’m also a person of privilege being a white, cis, heterosexual male in the USA, so I am certain I had more access than others do. I’m a bearded white dude in the coffee industry… at least in the USA we’re a dime a dozen. That being said, I am fortunate that my college education was essentially steeped in public speaking, creating lesson plans, and doing intense research. So I feel like my background, though in a totally unrelated field has helped me immensely. While I had started doing teaching and training before I published the book (two people put their trust in me early on… Ildi Revi from the SCAA who had me help design some of the roaster education, and Mark Loring from Loring smart roast) I have to say that Modulating the Flavor Profile of Coffee is what really helped me gain people’s attention. The book I released about 5 or so years ago was also early to the scene. It was the right time because other than Scott Rao, no one had published much on roasting.

The content is based on my early experiments and research surrounding how timing changes during the roast affect perceived flavors in the cup. It’s more looking for trends, and not complete specifics when it comes to flavor. Though I had assumed that all coffee would be totally different, trends in the data started emerging that seemed to point to similar broad flavor changes connected with roast timing changes.

Whats App Image2019 11 19at15 22 4521

On a volunteer basis, I helped to design a lot of the legacy SCAA curriculum as well as help with the merger when the SCAA (Specialty Coffee Association of America) and SCAE (Specialty Coffee Association of Europe) merged. As I mentioned earlier, I was already accustomed to educating adults, so this was a natural fit for me. I also mentioned earlier that Ildi Revi saw something in me and took a chance. That came in 2013 when she conscripted me into the SCAA in the early 2000s and said: “You’re going to China to teach the entire SCAA curriculum.” 

After that trip to China, I was tasked with reworking a number of the legacy SCAA classes like: Profile Roasting, Grind Particle Analysis, and Heat Transfer. I was eventually elected to the Roasters Guild Executive council where I started as the co-chair of the Education department, and eventually went on to chair the Education department. I am one of the last original members of the SCAA curriculum creators group that is still actively contributing for the Roasting Pathways.

Why is roasting such a big deal? What’s the process behind it?

Rob: People who produce coffee put a lot of time, effort, and energy into making specialty coffee. And the truth is, you can pretty easily and pretty quickly mess up the nuanced flavors that they worked hard to produce. So… while you cannot necessarily make bad coffee good through roasting… you can make great coffee just okay, or worse. You can make great coffee taste bad. That is why what we do is so vital. We are taking part in a transformative process as coffee roasters and it is up to us to carry the inherent quality through to the final product.

The process behind roasting seems simple, and at face value it is. Essentially, I have spent a majority of my life learning how to turn green coffee brown. 

It is a simple proposition of heat energy applied over time, however there is a lot of room for finesse when it comes to roasting. How brown you turn the green coffee is most important.

BB BGA Roasting 002

Ongoing research by my friend Morten Munchow from Coffee Mind in Copenhagen shows that the final color (whole bean and ground) is the most significant modifier of flavor. However, how quickly you turn that coffee brown is also important. Specifically, how much time after the beginning of “first crack” (when coffee sheds much of its water content and expands due to vapor pressure) is an important player in the development of coffee flavor. How quickly the roast gets to first crack is also crucial.

What makes your ideal roast?

Rob: I love acidity. I’m a huge citrus fan. My ideal coffee has really nice citrus notes; peach, orange, grapefruit, kumquat. My roast will accentuate that without being overly sour or sharp. Sweet, citrus, and floral are my jam.

The best coffee I ever got my hands on was the coffee I roasted for a Danish competitor from a Barista Championship. I roasted for her and got it from Granja la Esperanza in Colombia. It was a mix of citrus and fruitiness with huge floral tones, and this crazy eucalyptus mint floral thing going on. It didn’t matter how I roasted it actually - it tasted different every time, but good.

How did all this lead you to Bettr Barista?

Rob: Pam emailed me out of the blue after I published the book actually, asking if I would come and teach. I was very excited to do so. Nobody had ever reached out to me before to come so far. At the time, I was getting a lot of requests and was skeptical overall. So I learned more about Pam and Bettr Barista and became super excited to come out. 

After I came and saw the good work being done, I just decided: I won't teach SCA curriculum anywhere else in Asia. Only here. Every year since then, I’ve done an annual roasting class with Bettr Barista. Of course the exception being this year due to COVID.

Given all that you’ve established in roasting, what’s your vision for the industry?

Rob: I have some concerns about the future of coffee and coffee roasting if I am being honest. The economic pressure being caused by COVID on roasters, baristas, coffee producers, the whole chain is in a difficult spot. Couple that with an existing coffee price crisis due to antiquated colonialist systems at play within the coffee industry and those we rely on most, producers, are bearing the largest burden. 

On top of that, climate change marches forward! We’re looking ahead at a future where coffee is more scarce, so we need to have fewer mess ups when roasting. We’ll need higher prices to consumers to sustainably support everyone involved.

Any tips and tricks for home roasting?

Rob: Just enjoy it. That’s the biggest thing. There are a lot of people out there with strong opinions about coffee roasting; especially on the Internet. We get into roasting because we enjoy it, not because it makes us wealthy. Make sure to keep doing things that bring enjoyment for you. Take diligent notes. Limit your variables. Approach your roasts with a scientific mindset, and use scientific methodology

We don’t know everything about coffee roasting yet, so we need to enjoy what we’re doing to keep moving along.


If you enjoyed learning about the intricacies of roasting coffee, subscribe to Bettr Barista’s newsletter and follow our social channels to be the first to find out when Rob will be with us, virtually or in person.