|
Stage
|
Bean Properties
|
Mass Loss
|
Agtron Number
|
Temperature (F)
|
Bean Appearance
|
| Unroasted |
Raw bean is 12% water by mass. |
0.0%
|
99-81
|
Room Temp.
|
Green and smooth.
|
| Cinnamon |
Volatile vapors cause bean to expand. |
13.0%
|
80-75
|
200-275
|
Light brown. Grainy grassy smell. Light body, minimal aroma,
tea-like flavor. No oil on surface of bean.
|
| American |
Bean is still expanding. This is the stage where
"first crack" begins. Acidity content higher than sugar. |
14.0%
|
74-65
|
335-375
|
Darker brown. Larger in size.Bright acidity, green coffee distinctions
clear. Surface of bean remains dry.
|
| City |
Bean almost at maximum expansion. "First crack" stage is
finished.
|
15.0%
|
64-60
|
390-425
|
Beans show physical cracks from release of gasses.
|
| Full City |
Bean at max expansion.
Balance of acids and sugars. "Second crack" stage has just started. |
16.5%
|
60-50
|
435-445
|
Bean chips begin to fly off. Smooth and
brown. Oil is barely visible. Balanced acidity, fuller body. Generally dry bean
surface.
|
| Vienna |
More gasses are lost. "Second
crack" is finished. |
17.0%
|
49-45
|
445-455
|
Dark brown. Beans have oil on them. Hints
of bittersweetness emerge. Muted acidity, heavier body.
|
| Espresso |
Aromas decrease. Sugars
caramelize. |
18.0%
|
44-35
|
455-465
|
Black and spots of oil, shiny surface.
Bittersweet roast notes dominate
Acidity and muted.
|
| French |
Acids radically decrease.
Sugars caramelize. |
19.0%
|
34-25
|
465-475
|
Dark black. Very oily. Burnt smell. covered
brightly with oil. Bitter/bittersweet tones dominate. Body thins, green coffee
distinctions are fully muted.
|
| Italian |
Bean loses characteristic
coffee flavor. |
20.0%
|
24-15
|
475-505
|
Black, oil is dried off. Shiny surface.
Burned bitter tones dominate.
|
