Roasting is the collaboration of both art and science, because of this it is difficult to pinpoint or say what is right in terms of roasting profiles, but today we'll look at one process that happens during the roast and how it impacts what's in your cup.
*Maillard Reaction*
In the simplest terms this is the stage of cooking when things start to go brown. This isn't exclusive to coffee and happens just the same when you are cooking vegetables in your frying pan. When coffee is roasting at very high temperatures, the proteins will begin to break down into amino acids, that then quickly react with simple sugars, a source of energy for our bodies.
The longer that we roast our coffee, based on moisture, density and size, we will start to draw out a heavier body & notes associated to chocolate, nuts and not surprisingly given what was said above, sugars. These roasts would tend to be leaning towards what we call medium or dark roasts.
If we were to shorten the reaction we would start to get a lighter body with notes associated to fruity, floral and sour coffee, this makes sense as to why lighter roasts of coffee have such high acidity.
*Results*
Roasters are constantly tinkering with the maillard reaction to get different results; they might be aiming to get dark chocolate notes so prolong the reaction or achieve something closer to the taste of grapefruit and shorten it. This is not an easy job and from all the roasters I've met they all have differing ideas on what they want to produce, which for me makes it even more exciting.
How do you like your coffee roasted?
Would you rather the maillard reaction was longer to get more chocolate flavours or shorten it and get those powerful fruity notes?
Jon Townsend