Roasting

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Roasting: The process of turning green coffee beans over heat to force moisture out, bring volatile oils closer to the surface and release the essence of the bean's flavor.
 
The beans are heated in rotating, horizontal drums that provide a tumbling action to prevent uneven roasting or scorching. Temperatures for roasting range from 380 to 425¡ Fahrenheit. Precise temperature and timing make the difference between an excellent roast and burnt beans.
 
Roasting changes the chemistry of the bean by converting the starches to sugars, known as "developing" the bean. During the roasting process, most of the moisture is cooked off and the beans lose 18 -20 % of their weight. However, the beans gain smoothness, a caramel taste, and a bitter edge. During the roasting process, the beans actually plump up to double their size. Once roasted, the beans require rapid cooling.
 
Coffee that is neither roasted long enough nor hot enough to bring out the oil has a pasty, nutty, or bread-like flavor. Coffee roasted too long or at too high a temperature is thin-bodied, burned, and industrial-flavored. Coffee roasted too long or at too low a temperature has a baked flavor.
 
Beans can be roasted at home by using an ordinary frying pan. Stir often or the beans will burn. A hot-air popcorn popper also does very well. The temperature is just right for roasting coffee, and the motion of the air will keep the beans moving quickly so they don't scorch. At first, the beans will be too heavy for the hot air to move them, so stir them constantly until they start moving.

Light:

  Appearance: Light brown; dry surface.

  Flavor: Tastes more like toasted grain

  than coffee, with distinct sour or acidic tones.

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Medium:

  Appearance:Medium brown;dry surface

  Flavor:  A definite acidy snap,

  but riche toned and sweeter than light roast.

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   Dark:

    Appearance:Very Dark brown; very shiny, oily surface 

    Flavor: Burned or charcoal tones plus a bittersweet

    tang; all acidy tones gone.

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Light or Full City Roast - A light or full city roast is achieved when the natural sugars have caramelized. The beans have a rich brown color.

Medium or Vienna Roast - At this point the natural sugars in the bean have begun to burn. They are just at the edge of darkness. The oils in the beans are just beginning to surface and the beans are a darker brown than light roast. This level of roasting produces a very full, rich flavor

French Roast - Once the natural sugars are burning, we have a French roast. The coffee oils have come to the surface and the beans are dark brown. With this roast the character of the burning sugars starts to compete with the regional character.

Italian Roast - We've burnt the sugars here! The result is a very dark brown oily bean. The bittersweet flavor is a result of the dark roast.

Note that burnt does not mean strong. "Strength" in coffee properly refers to the proportion of coffee to water not the flavor of the bean.



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