Airflow 'mistake' results in sweeter coffee? - Page 3

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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Boldjava
Posts: 2765
Joined: 16 years ago

#21: Post by Boldjava »

day wrote:I don't see anyone really explaining what the airflow is doing that results in change of sweetness. . .
In a drum roaster, 70% of heat transfer in a roast occurs via convection. Proper use of airflow is critical for that transfer of that energy during convection aspects of roasting. Mismanage that airflow, you are going to impact not only the sweetness factor but the flavors and acidity as well.

OP talked about a sweeter coffee with reduced airflow during the entire roast. For me, that is logical. His post suggests he moved quickly through the middle phase, caramelization/maillard, leaving it sweeter.
Caramelization begins at approximately 340°F (171°C),as the
heat of roasting breaks apart molecules of sugar and produces hundreds of new
compounds, including smaller, bitter, sour, and aromatic molecules and larger,
brown, flavorless molecules. Although most people associate the word "caramel"
with a very sweet dessert food, caramelization, ironically, decreases the
sweetness and increases the bitterness of a food or beverage. Lighter roasts
are sweeter
. http://www.scottrao.com/Coffee-Roasters-Companion.pdf
..I hadn't increased airflow as I usually do from tan to 1stC. . .it was the sweetest roast of this coffee we have ever had. ...
I don't think we can push our points any further than that unless we were around the cupping table with a couple of his coffees, discussing charge size/temp, profiles, drop temps, roaster brand, application of BTUs, airflow settings, and RPMs of drum if available.

I am going to try and mimic his roast (have a profile to post?") and see if I can replicate his "error" and draw some real conclusions based on cups rather than speculation.
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LMWDP #339

Chargerswin
Posts: 24
Joined: 8 years ago

#22: Post by Chargerswin »

TomC wrote:On my Ambex clone, the only time the fan is on high is when I'm cooling the coffee in the tray.
not to thread jack but what roaster do you have? I am not aware of an Ambex clone... Seriously curious.
Sonofresco roasters are better than yours ;).

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TomC
Team HB
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Joined: 13 years ago

#23: Post by TomC replying to Chargerswin »

Terry's main builder spun off his own business for a while, making identical roasters.
Join us and support Artisan Roasting Software=https://artisan-scope.org/donate/

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