You’re used to roasting washed coffees, and you’ve got your first natural processed beans? You don’t know where to start? Or you’re facing new experimental processing? Let me guide you through the ideas behind roasting different types of processing.
Washed coffees are the most common in the world. To quickly remind you, washed coffee after picking goes through a depulper to get rid of skin and mucilage, then it’s fermented typically for around 24 – 36 hours. This fermentation breaks down leftover mucilage, so it comes off easily during washing. Then it’s dried until around 12% moisture. This method is usually preferred by producers cause it’s fast, efficient, and the final cup tastes great. Washed coffees are usually slightly more dense and „heat-resistant”. Thanks to those properties, washed coffees are quite easy to roast. I would always start with a higher heat to get enough momentum in the first stage of the roast. Then, slowly declining after coffee is in the Maillard phase. When you’re getting close to first crack, it’s quite tricky, some coffees can be kind of super reactive, and when you decrease the heat right before first crack or right after, temperature increase can crash due to high moisture release. Avoid that by not changing your gas or power setting close to first crack.
Natural coffees are more and more popular thanks to their fruity sweetness with muted acidity. How is it different from washed? Right after harvest, cherries are soaked for floaters separation. Then coffee is placed on drying tables or patios and dried. Dry pods are „cleaned” of their dry skin and mucilage to be left only with the green bean. This processing results in slightly less dense coffee, but it’s slightly more vulnerable to heat, and it’s easier to scorch during roasting. To avoid that, I would go with short soak or start with medium heat when starting the roast. Close to first crack, natural coffees tend to experience a „flick”, which is a quick and uncontrollable increase in temperature. I usually avoid that by making small adjustments right before or right after first crack. Also, aim for slower and slightly longer development time.
Honey processing is somewhere between washed and natural, both in processing and taste. During processing, coffee goes through a depulper and then straight to drying with leftover mucilage. This yields coffee with slightly sweeter acidity than washed but not as muted as natural. In roasting, they are, in my experience, more similar to natural coffees. I would start slightly faster than natural beans, but first crack behaviour is unpredictable. It can be similar to washed, but also similar to natural. It’s a game of guessing and trial and error.
Experimental processing like anaerobic washed, infused coffees, cofermented, and others are hard to classify. My experience with roasting these processes gave me some idea of how to approach them. Usually, when I see that coffee is somewhat washed (dried only in parchment), it tells me to treat it as washed coffee, but you need to be careful with the final color. I think they are not picking up color as fast as regular washed, so it’s good to add 10 – 15 seconds to your development time. If coffee is natural or cofermented, or infused, they are the opposite. Treat it like a natural, but mind the color. Maybe you won’t even be able to hear first crack, or it will be a couple of degrees higher than usual, and they tend to pick up color much quicker. It’s not necessarily a bad thing. I think they taste more balanced when roasted slightly darker, but it’s personal preference.
I hope this will help you roast delicious coffee on your first try. If not, remember it’s always a trial-and-error game. Roast, cup, repeat as they say 🙂
Our step-by-step roasting guide & roasting tips has been design for you by Aleksander Smet, 2022 Polish Roasting and Cup Tasters Champion.
