A medium roasted coffee means that the coffee has hit first crack and then undergone a completed development of sugars within the bean to create a balanced roast. It stops far shy of second crack, but some of the oils may still express themselves during the roasting process. Medium roast coffee will be medium to light-dark brown in color. The individual characteristics of the coffee will just begin to give way to the roast’s flavors and aromas, resulting in a sweet balance of acidity and body. Medium roasts tend to have fuller bodies, as the sugars are developed but not broken down. The beans won’t be as brittle as a dark roast, and generally have a more even particle size than fragile dark roasts when ground.
Nope! There is a range in which medium coffees can fall in and still be considered “medium”. There is different equipment in the industry to determine this range, Color Track, Agtron, and Javalytics among many others. To be considered a medium roast, the coffee has to be medium brown and have flavors and characteristics indicative of the green coffee, with the flavor fully developed. There are many ways to go about this, and it’s up to the skill of the roaster to nail that medium roast.
Medium roast is less acidic than a lighter roast. Heat breaks down a lot of chlorogenic acids during the roasting process, and the longer the coffee bean is exposed to that heat, the more those acids break down, making the acidity less perceptible. A medium roast also has more developed sugars, flavors, aftertaste, and body to balance the acidity more evenly than a lighter roast, which has much less development overall.