Roasting Roasting Levels Storage
Coffee was first roasted in the late 14th century. The earliest method was by roasting the green coffee in a heavy pan over charcoal fire . Late last century, a new process was introduced where beans were spun in a hot air chamber heated by natural gas; this system is still the most widely used to date. With the birth of the computer technology has evolved and when coupled with light heating temperatures can now be maintained within +/- 1ºC.
The chemical make-up of the coffee bean changes during the roasting process: water dissipates in the bean and a series of chemical reactions change sugars and starches into oils, which give coffee much of its aroma and flavor. When roasted the coffee bean doubles in size and the caramelization of the sugar turns it from green to brown.
The color and appearance of the roasted bean depends on how long it has been roasted for. The longer it is roasted, the darker the roast. Coffee is usually roasted for about 10 to 20 minutes at temperatures ranging from 400ºF to 425ºF (204ºC to 218ºC).
The secret to developing the aroma and flavor of coffee is found in the roasting of the coffee beans. The length of time, as well as temperature of the roast, are crucial in producing a quality cup of coffee, as well as determining which characteristics will be emphasized or muted. If roasting is too short, the oils won't be brought to the surface and the coffee will have a nutty flavor and lack consistency.
Dark roasted beans contain less acid, have slightly less caffeine than lighter roasted beans and have a shorter shelf life, due to the amount of oils on the surface. In darker roasts, it is the roast's smoky, pungent, burnt taste that dominates overtaking the bean's natural flavor. Many times the dark roast's burnt taste will mask beans that are low in flavor and quality. Contrary to popular belief, a dark roast does not equal a richer, stronger cup. Roasting plays no part in determining the strength of a cup of coffee. It is the amount of water and coffee to be used when brewing that determines the strength.
Lightly roasted coffee beans have a sharper, more acidic taste than darker roasts. The coffee suffers less heat exposure, which maintains the bean's qualities. Because flavor is revealed, light roasts are used with higher quality beans.
Several roasting levels have their own characteristics and may be suitable to different tastes or specific uses; they are the following:
|Cinnamon Roast||light roast, light cinnamon tone||
||Pronounced nut-like flavor, high coffee acidity|
|American Roast||Medium roast, chestnut hue||
||Pronounced caramel like flavor|
|City Roast||Medium roast, medium brown with no surface oils||
||Full coffee flavor, with some loss of acidity|
|Full City Roast||Chestnut brown, slightly darker than the City Roast||
||Full coffee flavor, good balance of acidity and sugar|
|Vienna||Dark brown, with traces of oil on the surface||
||Dark roast flavor|
|French Roast||Dark brown, nearly black, oily on the surface||
||Bitter, smoky taste and pungent aroma|
|Italian||Dark chocolate brown, oils on the surface||
|Espresso||Dark roast, used specifically for espresso machines||
||Burnt flavor that is strong and sweet|
Aliases: Cinnamon roast, Half city, New England
Roaster Watch: After about seven minutes the beans “pop” and double in size, and light roasting is achieved. American mass-market roasters typically stop here.
Flavor: Light-bodied and somewhat sour, grassy, and snappy
Aliases: Full city, American, Regular, Breakfast, Brown
Roaster Watch: At nine to eleven minutes the beans reach this roast, which U.S. specialty sellers tend to prefer.
Flavor: A bit sweeter than light roast; full body balanced by acid snap, aroma, and complexity
Aliases: High, Viennese, French, Continental
Roaster Watch: After 12 to 13 minutes the beans begin hissing and popping again, and oils rise to the surface. Roasters from the U.S. Northwest generally remove the beans at this point.
Surface: Slightly shiny
Flavor: Somewhat spicy; complexity is traded for rich chocolaty body, aroma is exchanged for sweetness
Aliases: Italian, Espresso
Roaster Watch: After 14 minutes or so the beans grow quiet and begin to smoke. Having carmelized, the bean sugars begin to carbonize.
Surface: Very oily
Flavor: Smokey; tastes primarily of roasting, not of the inherent flavor of the bean
Green beans will last for around two years or so without any appreciable loss of flavor. Green coffee beans should be stored in some sort of container that will allow it to breathe and not impart another flavor to the beans: burlap bags, paper bags, etc. work best and it is recommended to try and avoid plastic containers. Storing them at room temperature is fine, however some experts suggest a cooler place out of direct light. An ideal environment is approximately 70 degrees F. and around 50% relative humidity.
Roasted Beans are another story completely and this is where subjectivity really comes into play. There is such a thing as "too fresh"! Immediately after roasting, most coffees taste pretty much the same - delicious, but the same. Freshly roasted beans need time to de-gas and cure to allow the specific nuances to come out in each of the varietals. At the very least you should wait for at least 4 hours, however it is even better to wait at least 12 hours or more. It is a good idea to only roast enough beans to meet your needs for about 4 to 7 days. This will ensure you are drinking the freshest cup possible. Some may extend that window to 10 to 14 days however a good coffee roaster might rather keep a spare canister around for the 10 day mark and make a nice blend. Roasted coffee stores best in a sealed canister at room temperature. There are numerous articles, some quite scientific, on preservation methods like vacuum sealing, refrigerating, freezing, you name it and the result is always the same - nothing stops the deterioration of flavor.
Now we're getting into a critical area! Only grind what you intend to brew! You can let your nose tell you how much flavor you may have lost even a couple of hours after it has been ground.
To summarize, good fresh coffee is not a gift to be saved for a special occasion. Store the green beans safely, then roast, grind and brew them as needed. For those of you who like routines, have a glass of wine while you roast a batch or two in the evening and your coffee beans will be ready for use the next morning.
Disclaimer: All coffees vary and it is the responsability of the roaster to check the coffee. This page is not a reference.