Roasting the Coffee Beans
A Minute-by-Minute Description
- 3 minutes: The beans emit a grassy aroma as the coffee begins roasting. The temperature rises to approximately 100 degrees Centigrade.
- 5 minutes: The beans swell up as they turn from bright green to pale yellowish and finally golden brown. At this point the fragrance is more like toasted wheat.
- 9 minutes: The beans start to furrow and wrinkle.
- 10 minutes: The beans reach 160 degrees Centigrade. Gasses swell up the beans to about twice their size. Complex chemical reactions occur and a cracking sound can be heard. The beans are about 150% of their original size. The beans rupture and release the gasses. The surface of the beans becomes smooth again, and the color changes to light brown. This is a Cinnamon roast, the lightest coffee roast.
- 11 minutes: The coffee bean color gets darker as elements within the coffee beans begin to caramelize—this is a Full or Full City roast. The cracking ceases and a silence occurs—how long depends on the temperature applied by the roastmaster.
- 12 minutes: The fragrance and color of the coffee beans changes quickly—they are brittle and dehydrated. Elements begin to carbonize, creating the Dark roast’s burnt sugar flavors. Gasses again swell the beans until they burst—this is “the second pop.”
- 15 minutes: The coffee beans darken considerably—this is a French roast (Italian or Espresso roast in Europe).
The freshly roasted coffee beans are poured into a cooling vat and stirred so they cool quickly and stop roasting. Quickly introducing large amounts of cool air is important in order to stop the roasting process.
The beans will emit vapors (gasses) for up to two days after roasting, and then the flavor of the freshly roasted, ground, and brewed beans is optimal.
If the beans are packaged directly after roasting they need to be in an air-tight bag with a one-way valve so the gasses can escape. See a detailed discussion of this in Brewing the Perfect Cup of Coffee.
Whole bean gourmet coffee properly packaged and stored in a cool, dry, dark place will retain its freshness for a long period of time. If the gourmet coffee is exposed to air, however, the flavor will deteriorate quickly, much of it being lost after just 7 to 10 days.
CoffeeManDan Says, “The top European Coffee Consumers (per capita) in order of consumption are: Finland, Denmark, Sweden, Holland, Belgium, Norway, Switzerland, Germany, Austria, France, Italy, Hungary, Greece, Spain, England, Portugal, and Iceland.”