Roasting Naturals - Ethiopia

Roasting Naturals - Ethiopia

by Christopher Schooley

I recently had a discussion with a roaster who was having difficulty with a natural dry processed coffee from Ethiopia. He did not have much experience roasting DP coffees and had not really even considered how coffees processed in that style were different. He believed that the problems that he was finding in the cup were the result of the beans not all being of a uniform size since he was not having similar problems with other coffees that he was roasting (which happened to all be washed coffees and thus of a more uniform bean size). So his response to his difficulties with this coffee was to separate the coffee by screen size in order to achieve uniformity. This did eliminate the "off" tastes that he was getting, but those "off" tastes could have been taken care of by adjusting the way that he was roasting, and what he ended up doing was changing the character of the coffee by separating out non-defective beans, beans that actually added to the overall quality of this coffee and in fact the Longberry bean shape of the Ethiopian heirloom varietal led to his separating almost 40% percent of this coffee out of what he planned to roast. I've personally done the DP Ethiopian green coffee sort and cupping experiment and my own results were that the more uniform selection had perhaps more balance, but lacked the sweetness and complexity that the coffee had as a whole (unseparated). Tom has done the experiment with a washed Ethiopia Yirg, here: and had some insightful findings but ultimately reached the same conclusion.

Now as I said, this is someone fairly new to roasting and I'm not trying to simply point out a mistake but to use this opportunity to note one or two or more things:

1. Bean size indicates bean size, not quality.
2. A washed or Wet Process coffee goes through a level of separation that Dry Processed coffees don't, but that doesn't mean that a DP coffee is full of junk and defects just because the beans are different sizes.
3. Removing quakers from a coffee should be done after the roast, this cannot be achieved through a bean size separation.
4. The variation in bean size which is common in DP Ethiopian coffees does dictate that it is important to allow the coffee to move into a full and vigorous pop before reducing the gas rather than making an adjustment right when you hear the first signs of popping.
5. Your answers are in cupping and roasting, and then doing it again.
6. If you're having a problem with a coffee, ask another roaster. One of the things that I've most enjoyed about Coffee Shrub are the comments from other roasters and the idea that people can share their experiences with a coffee, or their difficulties, and get some feedback, advice, and encouragement from others.

15 screen Ethiopia Maduro DP15 screen Ethiopia Maduro DP
Everything that passes through a 15 Screen on Maduro , but because of the longeberry bean form, many things get through that would not on another coffee with the same bean length, The real issue is what the significance of bean size truly is ... if the coffee cherry was ripe, processed and dried well, there is no reason for a smaller bean size to be of any less quality in the cup as a larger bean. In fact, there is a chance that smaller bean sizes are more dense seeds, and could be better in the cup


#1 Hey roasters, I have tried

Hey roasters,
I have tried this coffee and am left with some lingering questions [Much like the aftertaste, but not as yummy]. Any suggestions would be more than welcome, as I am a new roaster as well. I am roasting on a probat L-12.:
1. How do you remove the quakers after a roast without going insane?
2. If indeed the coffee was picked at the ultimate of ripeness, and quakers are an indication of under ripe cherries, how is it that this coffee has so many quakers
3. Not to pick on quakers excessively, but they do seem to show up much more in a lighter roast. Do you have the same experience, and does this really mean, as it seemsto, that some of the quakers are eventually picking up roast color and being passed over in a post roast visual screening?
4. Does anyone know of a way to remove quakers other than visually and post roast. (As you know, this is not the only coffee around that has quakers). I sit there are watch the coffee as it goes around the cooling bin, and assuming I am paying attention, maybe I get like 75% of them in the 3 minutes. I can't see how you would go about it once it is dumped into a pail. Spreading the 10+ lbs on to a table/ cookie sheets is possible, but man is it awkward and time consuming, not to mention for sure you are going to spill some on the floor.
5. I just brewed (as a pour-over) some of this coffee that I roast really light , like 6 weeks after I roasted it. It stills tastes great. Any idea why?
6. The very tiny beans, strangely enough, seem not to roast much differently than the larger ones. This is counter intuitive (at least to me!). Any idea whether the small beans reach crack first, and if they do crack at different time/temp could this account for the increase in complexity when roasted together?
Interestingly, when I roast this on a 2 lb sonofresco (air) roaster, the chaff more often than not catches fire in the collection screen, at anything close to second crack.. This causes the roaster to shut down prematurely, and leaves me with either an unusable roast or scrambling to throw the beans (which are clearly NOT on fire) into the cooling tray of the probat, so that I can cool them.
Happy roasting!

#2 I recently assembled a little

I recently assembled a little "roast off" with seven other roasters using the Maduro.
It was interesting to find that done well it could be deliciously sweet and complex but dragged on excessively and sent into second had kitty litter and smelly shoe funk.