Consumers are no longer content with commercial standard instant coffee and appreciation of high-quality beverage is on the increase. Coffee is second most traded commodity globally and there are different levels of getting the desired taste.
Medium roast coffee is the second roasting level after the light roast. The coffee beans are brown in color and make a sweet caramel brew for coffee lovers while the dark roast goes through a longer roasting process than the medium giving it a dark chocolate color and bitter-sweet taste.
Here are some of the differences between the two roast levels and benefits of both roasts.
How are coffee beans are roasted?
Roasting is the process of using dry heat to enhance chemical changes in coffee beans which result in physical change and variety of taste, flavor and aroma. The main types of roasters used are: The drum roaster and the Air roaster.
Coffee beans are put into a drum roaster or a cylindrical shaped chamber and as the drum rotates, the coffee beans are heat from below. Air roasters use flow of super-heated air to roast the coffee beans. The beans roast in temperatures of 370°-540° C, and they change color from the natural green to medium brown and finally dark brown.
After the roasting, the beans are cooled by various processes including the vacuum system or quenching where water mist is used and are immediately packed to maintain freshness.
Medium coffee beans are roasted between the end of the first crack and the beginning of the second crack at a of temperature of 210°-220°C (410°-450° F) while the Dark Roast are roasted for an extra 30 seconds after the second crack at a temperature of 221°-232° C (430°-450°F).
Roasting is perfected over time and it is a skill that requires proper balancing of heat and time.
Difference between medium and dark roast coffee
|Roasted at 410°-450° F
|Roasted at 430°-450° F
|Has a rich brown colour without oily surface
|Has a dark brown colour with oily surface
|Has a sweet aroma and even flavor
|Has a strong aroma and harsh bitter-sweet flavor
What is the roasting temperature?
Medium roast coffee is roasted at a temperature of 210°-219° C. This is between the first audible crack and the second crack while roasting. The beans are immediately taken out and cooled. The dark roast are then roasted for 30 more seconds after the second crack at a temperature of 221°-232° C before they are removed for cooling and packaging.
Coffee absorbs moisture and becomes stale fast, it is best to store them immediately after the cooling process into airtight containers.
Is medium or dark roast coffee stronger?
Dark roast is confused to be stronger due to the rich flavor and bitter spicy taste it has as the medium roast maintains a sweet caramel flavor. Medium roast coffee has a well-balanced aroma and flavor compared to the light and dark roast beans. While the light roast maintains its flavor during the first level of roasting, the medium roast beans go through a caramelization process getting a sweeter taste than the light or dark roast. Dark roast however goes through a longer heating process and get an intense bitter taste with bold aroma.
The woodiness and harsh flavor of dark roast coffee, makes it best for alertness and for a morning cup but the medium roast contains slightly more caffeine due to the difference in bean size from roasting.
Roasting is the only reason why coffee gets a variety of flavor and taste. Medium roast coffee caramelizes from the medium roasting process with medium heat and timing to give the bean a sweet caramel taste and soft fruity flavors.
Dark roast coffee beans have a bitter-sweet taste and bold aromas from the longer roasting time. Robusta coffee beans have higher levels of phenylindanes making them more bitter when dark roasted.
The medium coffee roast has more body size than the dark roast therefore having more caffeine content. During the dark roasting, more caffeine is burned off as the beans are roasted for a longer period and lose body mass.
The caffeine levels decrease because of change of size after bean is roasted but the caffeine is chemically stable through the entire process.
Look/ physical-chemical changes
The main chemical change coffee beans go through is the Maillard reaction. The reaction process influences the flavor of the beans and also the appearance. The medium coffee roast gets caramelized resulting to a caramel, nutty sweet flavor and get a brown color with no visible oil on the surface.
Dark roast coffee goes through a longer roasting process and becomes dark brown in color and have oily surfaces due to the high heat. The beans also lose their mass and becomes less dense.
Is dark roast coffee more bitter?
Dark roast coffee has a bitter, spicy taste due to longer roasting time and high temperature. The chlorogenic acid lactones in the coffee beans are broken down to phenylindanes when the coffee bean is roasted for a long time thus the coffee beans taste bitter after brewing.
Which roast coffee is the strongest?
Dark roast has less caffeine compared to medium roast because the dark roast decreases in volume in each bean while roasting. Beans become less dense and have less caffeine but the dark roast bean has a more bitter taste compared to the medium roast. The bitter taste is normally mistaken for high caffeine levels. Dark roast coffee has a bold aroma and is preferred to boost energy and increase alertness.
Which coffees is healthier?
Dark roast has more health benefits than medium roast. The medium roast has polyphenol chlorogenic acid and antioxidants that boost metabolism and help reduce body weight while dark roast coffee beans are rich in antioxidants such as glutathione that help to restore dead skin cells. Dark roast coffee also helps to reduce toxins and weight loss is faster than medium roasted coffee beans.