This is my current process for finding a profile for a new coffee. One that I do not know:
- I consider where the bean came from.
- I consider what kind of processing it underwent.
- I consider what my purpose is for this bean.
Once I can answer those questions, I then select an end time and temp.
Let's take for instance the Ethiopia Sidamo that we recently purchased. I know that this bean is from East Africa, which tells me certain things to keep in mind. High altitude can mean incredible acidity. The more extreme growing climate can mean a smaller, tougher bean that will take on heat well. It was naturally processed, which means it is going to have a fruit-forward character. I know that Ethiopian Naturals are a bean that Mocha Joe's and its customers love, and I need this bean to shine.
Because of these criteria I am going to pick a 12:00min roast where I end around 405F-410F.
I chose the time to be 12:00min because I want to keep the acidity forward. If I stretch a roast beyond this I know that I am losing acidity. Often I chose to lose some acidity in order to gain other desired flavors. On our roaster, anything over 13:00min means that we are introducing roast characteristics into the cup. I want to avoid those flavors in this case. Since it underwent a Natural Process I want to let those fruit and floral notes remain in the cup, that's why I kept the temp so low at 405F-410F.
The first batch I roast with a bean is always a balanced profile. What I mean by that is the point the Maillard Reaction begins, when the bean yellows, is exactly halfway through the roast. Once it yellows, the remaining time is evenly split between the Browning Phase and the Development Phase. Before the roast I choose the end time, and divide by two. That equation reveals when I hope to have this bean yellowing, beginning the Maillard Reaction. I divide that number one more time, getting a quarter of the entire roast. That is the amount of time I aim to have the bean in both the Browning Phase, and Development phase.
I was hoping the first roast of the Sidamo would have these details:
- Yellowing 300F 6:00min
- First Crack 390F 9:00min
- Dropping 415F-420F 12:00min
I roasted it that way. I then allow the roast to sit for a day before I try it. Gasses are being released from the coffee beans for several days after the roast, but the first 12-24 hours see the biggest release. I take notes when I brew it. I brew it multiple times over about a week and see how it changes in time. I take note how it changes over the week, but I also note how it holds up as it cools each time I brew.
I adjust the next roast according to my notes. Generally, I keep the end time the same and ajust the ratio of Browning and Development. If I want to change parts of the acidity or brightness I adjust the duration of Browning. If i want to change the sweetness and mouthfeel I adjust the Development. Every bean is different, and every machine is different, but those are general principles from which I start.
With the Sidamo, I found the acidity to be too forward, and when paired with the Natural characteristics, I found it unpleasant. The experience in my mouth was too high-end and tight. It wasn't sour, it was more like a strong hibiscus tea. There was no weight to counter the acidity. It needed more sweetness.
After a couple batches I came to a profile that read like this:
- Yellowing 300F 6:07min
- First Crack 392F 9:04min
- Dropping 418F 12:30min
I found keeping the Browning Phase as close to three minutes as possible was where I liked the acidity. I also noticed an increase in sweetness by adding nearly 30 sec to the Development time. But what I found wonderful was that roasting it 10 degrees higher brought out chocolate notes in the finish. It is still far away from second crack, but because of the traits of this particular lot of beans, the chocolate pops out early. The body is incredibly smooth and creamy and I think it's highlighted as the sweetness becomes more prominent. This was a great bean to profile. And it's been the coffee that's brewed in the morning since we've figured out the profile - we love it.