Eleven years ago, when I started producing coffee in the Dota mountains of the Tarrazu region in Costa Rica, I did not do the roasting personally, I used to take it to a roaster and even though I was there all the time and got involved in the process, the roasting was somebody else's craft.
A few years later I decided that to master my product completely I had to roast it myself. Once I got into it felt I had found my true calling: shaping the flavor of your coffee in 15 to 20 minutes is what it is all about. It does not matter how good the coffee grows and how much care you put in the process, if the roasting is not good, then the coffee quality that you worked for is ruined, or at least diminished.
So, how can the roasting spoil coffee? "Roasting is the key factor in driving the bitter taste in coffee beans", says Dr Thomas Hofmann, a German expert in Food Chemistry and Molecular Sensory Science. "So the stronger you roast the coffee, the more harsh it tends to get". He adds that "prolonged roasting triggers a cascade of chemical reactions that lead to the formation of the most intense bitter compounds. The roasting process changes the chemistry of the coffee bean".
This concept answers many questions, like Why Starbucks coffee tastes so bitter? Why does Starbucks coffee have a taste almost like it is burnt?
I have been telling people for years, both at the farm coffee tour and at my store, that the lighter roasts are the better cups of coffee, technically speaking. At the same time, i tell people that there it does not make any sense to swimm against the current, you like what you like. But if you have a chance, give the lighter roasts a chance. The light roast might be too much of a change but the medium is the perfect point to start.
If you prefer Darker roasts, you are safe with my dark and my espresso roasts. As a principle I dont roast as dark as the commercial brands so you would not find that extreme bitterness in them. I actually had to adjust my Dark roast standard because i would often get emails from customers who expected it to be "stronger" or show more of a "shine". These two are the characteristics of a dark roast like the one that Dr Hoffman described above.
I hope this article provides enough insight in your coffee. Knowing what you like and how it comes to be that way is key to know where you are going to go next.