Playing with roast profiles

So this week I decided to take on a challenge. I find that the French Press often does best with darker roasted coffee. Light roasts tend to get a bit sour or underwhelming in the full immersion method. So I wanted to see if I could shape my roast profile to produce a light roast that worked well in a French Press. I also wanted to play around with my old FreshRoast SR500, which is a small-capacity home roaster that works much like an air popcorn popper.

I started with three small batches of my Colombia: El Diviso. My Goal was to roast all three batches to the same level, City+ (medium-light) but to change the drying and browning (caramelization) time. I did a control roast that matched my current profile for the coffee and then one roast with a shortened drying and browning phase and one with a lengthened drying and browning phase. After that phase was complete and the coffee hit first crack, I tried to keep the profile the same, ending each roast at about 30 seconds after the end of first crack. My theory (based on research and my own personal experience) was that the coffee with the longer overall roast time would do best in the French Press. I also wondered if the shortened roast time would do better than my control roast in a pour over.

Here were my results from the cupping table 1 day later.

  • Short roast: Best aroma, flavor was slightly bitter as if the beans had scorched a bit (I probably pushed the roast too fast), the brightness was intense. The overall flavor of the coffee was pleasant, but fleeting and a little flat. Lots of grapefruit and lime. The body was also thinner than the other two coffees.
  • Control roast: Best overall balance. Still a nice punchy acidity, but more tempered with sweetness. Flavor was dynamic and lingered a bit. This is just the way I remember it when I first tried it as a sample.
  • Long roast: Best body and sweetness. The prolonged drying and browning caused a pretty dramatic shift in the coffee. The acidity was reduced, though still very present, this faded into a luscious sweetness that lingered for a few minutes on the palate. The coffee took on a more nutty/caramel flavor and the subtle herbal notes were emphasized. The body was quite a bit stronger.

So I took the roasts and tried them in the French Press. And sure enough the long roast was much better than the other two roasts. What was interesting, is the sweetness that became so central in the long roast just continued to intensify as the cup cooled. The only complaint I would have is that the reduced acidity tasted a little sour and was not as snappy as the faster roasts. I do think there may be a sweet spot between the control roast and the long roast that could bring out this sweetness without greatly sacrificing the acidity.

Finally I did a second cupping a few days later. The short roast that had a hint of bitterness, now was very bitter (I definitely scorched this batch!). The control roast was again balanced and nice. The long roast was even sweeter. I do think I will still stick with my standard roast for this coffee as it offers the best balance, but the long roast is an interesting second option. It is always exciting to see how much you can do with a great coffee like my El Diviso by just changing a few variables.