New Hoos Article in Roast Magazine (avail to public)

#1: Post by **CarefreeBuzzBuzz** » May 4th, 2019, 10:23 pm

Open for discussion. Find the article here.

#2: Post by **yakster** » May 4th, 2019, 11:01 pm

Not that surprising given that they're using drum roasters for all their roasts.

#3: Post by **Almico** » May 5th, 2019, 12:13 am

Two takeaways for me: "The second takeaway is that there are too many statements in our industry that we say as if they are fact, when the reality is that they are often merely untested opinion."

That's true in many industries, but it's remarkable to me how little true expertise there is in the $80 billion coffee industry.

The other is the request to coffee roaster manufacturers to please stop selling your roasters based on how they make coffee taste. Ouch.

I can say from my little corner of the coffee universe, there is virtually no difference in taste between my air roaster and my cast iron drum machine. I've found the drum machine easier to maintain consistent results, but like the premise of the article, once I learned to control the new roaster and match my profiles, the taste of my standard blends is unchanged. I have not had one customer ask me if something was different when I changed roasters.

#4: Post by **hankua** » May 5th, 2019, 9:29 am

Wow, that was a lot of work generating such a large data base; very impressive! Couple of misses with the article: I was unable to read the charts, which was unfortunate. Secondly the data would be easier to interpret if they ran it thru a statistical software program using several different charting functions.

#5: Post by **crunchybean** » May 5th, 2019, 11:17 am

I want to say this is just the research being published to the theory that was purported here:

#6: Post by **yakster** » May 5th, 2019, 2:04 pm

Great video with lots of meat to it.

Here's my takeaways or the things that sparked my interest:

Rob talks about sample roasting in large production roasters using the exhaust temp instead of the thermocouples. This is pretty much how I handled roasting with my Behmor, once the fan kicks on.
Interesting comment about infrared sensors measuring the heat above the beans
Talking about roasting to your water is familiar but roasting to your brew ratio and cupping at your intended brew ratio was something I hadn't considered but makes a lot of sense
Hard beans hold more moisture than soft beans at the same moisture %. This reminds me of how relative humidity works as well, at higher temps, the air holds more moisture so 70 % RH has more moisture at 90 F than at 70 F.
Rob emphasized that timing of the roast milestones is more important to match roasts than profile curves. The milestones should match within a second and the roast color should be within one point.

#7: Post by **Almico** » May 5th, 2019, 2:23 pm

yakster wrote:[*]Rob emphasized that timing of the roast milestones is more important to match roasts than profile curves. The milestones should match within a second and the roast color should be within one point.[/list]

Not sure I agree completely. If it were possible to have 2 roasts with the same Agtron roast levels for whole/ground, same time to yellow, same time to 1C and same DTR, and yet one roast has a big crash and flick, the two roasts would certainly taste different even though the milestone requirements were met. The destinations are important, but the routes to the destinations are as well.

But that was not the purpose of the piece. The purpose was not to determine if it was a good roast, just to be able to match the taste (good or bad) from one roaster to another.

#8: Post by **drgary** » May 5th, 2019, 3:25 pm

Almico wrote:Not sure I agree completely. If it were possible to have 2 roasts with the same Agtron roast levels for whole/ground, same time to yellow, same time to 1C and same DTR, and yet one roast has a big crash and flick, the two roasts would certainly taste different even though the milestone requirements were met. The destinations are important, but the routes to the destinations are as well.

Although I can't prove it, which the article admonishes, there is support for Alan's point in the details of the article. At one point Rob worked hard to "trick" the Diedrich roaster into creating a similar profile to the others without introducing roast defects. In my amateur experience I can introduce an awful and consistent air baked roast defect on my perforated drum TJ-067 with an airflow that's too high.

Back on topic, here's the quote that sums it up for me:

"... despite large differences in design, style, thermocouple measurement/placement, and heat transfer controls, people cannot easily discern a difference between the same coffee roasted on multiple, different roasting systems, provided the aforementioned methodology of profile matching is followed.

And even more significantly ... those who did pick the "off/different" cup in the triangulation could not specifically/clearly identify which roasting system the "off/different" cup was from."

And, the implications for a roaster operator:

"... the roast profile is the primary driver of coffee flavor. Matching duration and timing of key chemical reactions (modulation phases) as well as the extent of sugar browning, pyrolytic reactions and matching end color (WB/GR) are the key elements to matching a flavor profile .... as a roaster operator, you are ultimately in control of the flavor outcomes of the coffee you are roasting. With thorough knowledge of your machine and your green beans, as well as any potential agricultural variations that may influence flavor, you can adapt to match any style of roasting you would like, provided that you know where you want a key chemical reaction related to a specific flavor to occur."

Which mimics what has often been said here. If you're not getting the results you want, the problem is often on the barista side of the handle.

#9: Post by **Roasty** » May 5th, 2019, 3:42 pm

Honestly, this seems like common sense . . . I wasn't aware that there was such a dogma about, all else being the same, that machines differed in the taste they produced.

I'd be much more interested to see Drum Vs. Fluid Bed, airflow or drum speed comparisons with the same modulation.

May 5th, 2019, 5:13 pm

There has been some discussion on recirculating air roasters vs. 'traditional' small (relatively) drum roasters. I have heard that Willem Boot has a preference for the traditional design.

Another (partial) viewpoint: