Why Roast Dark?

PHOTO CREDIT: http://www.hubcoffeeroasters.com/

We all know that before a cup of coffee is served or even ground for consumption, it first needs to undergo the most important part before brewing; Yeahp! you've guess it right! Roasting! A coffee bean needs to be roasted as it is not really palatable.

Unroasted or underroasted coffee bean is not very coffeelike, it may be the same bean that we used to grind, but its taste is different from the ones we used to drink. It is characterized by herby, leguminous and nutty in taste. This taste happens just after the first crack when roasting. Once it passes the first crack, it will now start to release its different identities according to roast level (light, medium, dark, city, french, italian). As noted, the roast level is a function of temperature and time. The higher temperature and the longer time used in roasting, the darker the roast is. From light roasts that is full of verve and energy to dark roasts that smells and tastes like roasted, woody, and smokey flavors.

As mentioned above, coffee roasting is a function of temperature and time just like in cooking when you order a meal in a fancy restaurant where the server asks you if you want your meat to be rare, medium or well-done. Same goes with coffee roasting, as the temperature increases and the roasting progresses, chemical reactions happens simultaneously converting organic chemical compounds thus, a light roast chemical components is different from a dark roast. This is where these beans got their identities.

So why dark roast? As much as I want to spare you guys from the chemistry part, I just can't help but give you an overview of what happens when a bean is being roasted, but I will keep it simple! A reaction called Maillard reaction is the one responsible for the conversion of these compounds, in laymans term, this reaction is called caramelization, or the browning of the substance just like when you grilled a chicken, these are the brown and sometimes black substances found on the surfaces of the chicken. A recent research conducted on a compound called N-methylpiridinium (N-MP) found out that it seems to have a significant inhibition on gastric acid secretion in the stomach, which possibly can prevent nausea or indigestion. The concentration of this compound was also found to increase as the roasting progresses because the compound is the result of the conversion of trigonelline. To cut the story short, dark roasted coffee beans may make for fewer upset stomachs due to inhibition of gastric acids from the stomach. 

For the common Joe who addresses the taste according to roast level, well you are correct, related literatures repeatedly show that as the roast level darkens, acidity, fruity/citrus, grassy/green/herbal, and aromatic intensity decrease. Similarly, roasted, ashy/sooty, burnt/smoky, bitter, chemical/medicinal, burnt/acrid, sour, and pungent flavors all increase. But wait! Before you conclude, these negative flavors only occurs due to some researches that examined at extreme roast cases.

Bottomline, there is no right answer for how light or dark any given coffee should be roasted. It is the roaster's job is to produce a bean that is well-balanced that is palatable. Besides, roasting is very subjective. 

For us, Liberica beans are best roasted dark. These beans full-bodied, strong, and bold flavor are released once roasted dark.