James Hoffmann explains coffee roasting

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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baldheadracing
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#1: Post by baldheadracing »

Finally, an entertaining video that I can point to my friends that explains why I roast at home and also why I think almost all roasted coffee that I have ever bought has been roasted mediocrely. (I'm definitely a mediocre roaster, but I can start with better greens so I end up with better coffee.) Yes, the video is full of simplifications, but all-in-all I think a nicely done video. 18:37 long
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maccompatible
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#2: Post by maccompatible »

12 minutes in and every profile he's shown so far crashes at first crack :shock:
"Wait. People drink coffee just for the caffeine??"
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baldheadracing (original poster)
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#3: Post by baldheadracing (original poster) replying to maccompatible »

Rao shows a similar curve is his "Coffee Roasting - Best practices" book, and he calls this style of curve the "Nordic exception" as "the crash doesn't seem to cause the beans to taste as baked as the graph would imply." Besides Square Mile, you'll see similar curves from cast-iron UG roasters from Tim Wendelboe, Coffee Collective, etc. (I haven't looked at Loring curves.) That is how I roast coffees that are dropped well before the end of first crack; I'd suggest trying it if one has a roaster with the characteristics of a UG and wants a very light roast. Note that I'm not saying that it is the best profile for all coffees or even that you will like the resulting taste.

Let the same roast keep going until it flicks, though ... :cry:
-"Good quality brings happiness as you use it" - Nobuho Miya, Kamasada

maccompatible
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#4: Post by maccompatible »

Interesting!! I'll have to give that a go when I get my lagom. I think my encore may have a stroke feeding it coffee roasted that light.
"Wait. People drink coffee just for the caffeine??"
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maccompatible
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#5: Post by maccompatible »

I couldn't wait. As my attendings used to say during rounds, "there's always something to learn." I tried a couple different variations of my usual roast profile. Typically I give my Quest a little burst of heat right before first crack to mitigate the drop, then cut the heat to 0 to mitigate the flick. This works quite well with making the graph pretty, but sometimes leaves the coffee tasting generic. Though I've had little success roasting washed coffees darker without doing that..

Anyway, first experiment was to cut more heat out during drying, prolong the yellowing, and then another tiny adjustment down before first crack. Let it do whatever it wants to during first crack, and drop before it threatens to flick. Here's my result:


The second experiment was to let it go hard during yellowing, cutting less heat during drying phase, but then cut quite a bit more out before first crack. Again, let it do what it will and then drop before it flicks. The result:


What's extremely confusing, is despite finishing all roasts at a lower temp than usual, and with less time and time percentage of post-first crack development than usual, the coffee looks NOWHERE near as light as what James Hoffmann showed as the start of light roasting for specialty roasters. I'm definitely confused by that display he made of roast ranges, but I'll give it a few days and taste these coffees..

All this time I thought I was roasting light and medium, when I really may have been roasting medium and dark. :oops:
"Wait. People drink coffee just for the caffeine??"
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Jeff
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#6: Post by Jeff »

maccompatible wrote:All this time I thought I was roasting light and medium, when I really may have been roasting medium and dark. :oops:
Far from "your fault" as there's no reasonable definition of "light" or any other roast level before somewhere around second crack out there. I have heard lore that Tim Wendelboe's "espresso" roast is now lighter than his "filter" roasts of the not too distant past. I can see the idea that better control and repeatability of the roasting process has allowed explorations that weren't reasonable in commercial roasting (at any scale) a decade ago. Now we've got roasters that are making quotes like "Dark, like Tim Wendelboe dark" not seem totally outrageous.

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#7: Post by Capuchin Monk »

maccompatible wrote: Here's my result:
Just wondering, do you have the exhaust at high during the soak, then reduce after TP, then high again just before FC?

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#8: Post by maccompatible »

Yep. I roast back to back, and leave the fan on high after I drop, then turn it back down during turning point. I've found that if I turn it down before I charge, the turning point happens at a much lower temperature, and makes the graph look very weird. I didn't notice a difference in taste between when exactly I turned the fan down, so I settled on doing it this way.

You probably also noticed that I don't always perfectly document every change I make in fan and heat. Neither roast showed that I turned off the heat at charge and back on at 1 minute. And one roast didn't show the increase in fan speed to 50%, but I did still do it.
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Chert
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#9: Post by Chert »

What roasters were featured? Probat , Loring and IMF? I did not recognize the forced air machine.
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Almico
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#10: Post by Almico »

Nice vid. Explains quite a lot for the interested coffee drinker.

He did irritate my favorite pet peeve when he stated that the specialty coffee industry tends to roast light to preserve "origin flavors"...like Costa Rica has a particular flavor?

Growing and harvesting methods impart flavors, processing imparts flavors, elevations and weather can impart flavors and most of all variety impart flavors. But geography...not so much. Bourbons, for example, have more of a particular flavor profile than the country where it happened to grow.

When you buy wine, the first thing you see on the label is the varietal. Do you want a pinot or a chablis? A port or a merlot? The country of origin is secondary. When you buy tomatoes do you look for whether it was grown in NJ or CA or do you choose a beefsteak, cherry or a plum tomato?

I just brought in maybe the quintessential example for coffee: a naturally processed Typica variety from Sumatra near Lake Toba. This coffee, roasted light, tastes far more like an 88pt, clean, juicy coffee from Guatemala than a peppery, cedar, leathery coffee typically expected from Sumatra. At the same time I sampled another coffee blend of the more typical Jember, Ateng, Garundang varieties grown in the same region and these two coffees couldn't have been more different. I'm having a hard time even deciding how to label the former, since using my normal Sumatra colored label would clearly misrepresent what this coffee is all about.

Hopefully I will get to see in my lifetime the specialty coffee industry (myself included) "marketing" coffee properly and not mainly by country of origin. "Single origin" is practically meaningless, and reduced to nothing more than marketing jargon, if the coffee is made up or 3 or 4 varieties. Single varietal, now that is saying something.

Rant over. Back to your regularly scheduled program.

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