About the Coffee:
Name: Duromina
Harvest: 2017
Plant Varietal: Ethiopian Heirloom
Process: Washed
Drying method: Parchment dried 7 – 10 days
Farm location and other Characteristics:
Country: Ethiopia
Region: Jimma Zone, Agaro District, Oromio region
Cooperative: Keta Muduga Cooperative Union
Altitude: 1900 – 2200 masl
Farm sizes: average one hectare
We were incredibly lucky to have Jenny Howell, Director of Sourcing, share with us some really cool info. Thanks Jenny!
The bean:
“Ethiopia is known to many as having some of the most well-defined, distinctive flavour notes in the coffee world. In 2017, we bought eight different lots of Ethiopians, all of which had beautiful classic floral Ethiopian notes with varying degrees of fruit, spice, and tea-like notes. Duromina, however, was noticeably superior each time we cupped it against our other seven purchases. It was, in fact, a star, even when remembering back over the last few years. This Duromina has exceptional body, clarity of flavour, and power.”
The farms:
“Duromina is located in the Jimma zone, Agaro district, within the Oromia region. Farm sizes average one hectare (approximately two and a half acres) and are situated at 1,900 to 2,200 meters above sea level ( 6,200–6,900 ft.). Duromina coffee is demucilaged and soaked overnight in cold spring water that moves down a 500-meter (1,640 feet) channel to reach the wet mill site. Demucilaging saves water by mechanically applying friction to remove the mucilage surrounding the beans, instead of applying fermentation followed by washing in long channels using large amounts of streaming clean water. The parchment is dried for 7–10 days, and each day’s lot of coffee is bagged independently.”
The cooperative:
“Duromina, which means ‘improve our lives,’ has been an exemplary small farmer cooperative since 2010, when 113 farmers established it. When I made my first trip to Ethiopia in 2010, I travelled with some folks from TechnoServe, a non-government organisation that provides agronomy, management, and business training. Its goal is to improve standards of living on all accounts. I saw firsthand the powerful impact this type of aid had for farmers—their improved quality and thus their access to specialty markets, which in turn allowed them to substantially raise the price of their coffee. TechnoServe worked with over 340 wet mills from 2008–2011 in East Africa.”
“Duromina was once part of the largest Ethiopian cooperative federation in the country, Oromia Coffee Farmers Cooperative Union. But in 2016 they formed their own union, Keta Muduga Cooperative Union, with several of the finest specialty producers in the region. This may have helped lead to their best year yet.”
George Howell: A Day in the Life
The roast:
Robert Roderiguez, roaster for George Howell Coffee, shared with us the background to how the Duromina was roasted:
“For our roasting operation at George Howell Coffee, we work with a Loring Kestrel S35 (built in 2012) and Probat UG-22 (built in the 1960’s). While the Loring is an absolute workhorse and extremely consistent roast to roast, we felt that it best to go with our Probat for the Duromina for the degree of control we have over smaller batch sizes. That control is afforded to us for a few reasons, in particular coming down to the dutiful machining of the Probat from the day it was built, as well as some of the modest and modern modifications we’ve made to it over the years. Due to our diligent upkeep and profile mapping via Cropster, we’ve been able to fine-tune our approach to ensure a consistent quality cup out of the Duromina.”
“We try to keep it straightforward here with our roasting. To do that we roast lightly, by using careful heat application throughout the roast to exemplify terroir, and let the coffee — as the work of the farmers — speak for itself. We find this clarity no more apparent than with this year’s Duromina.”
“To achieve this, we started off with a bean charge temperature of around ~168°C (~335°F). Once in the drum, we delay making any burner adjustments for about 20-25 seconds before incrementally adjusting the heat upwards, until we reach preferred maximum burner adjustment. This allows us to shoot for a peak rate of rise (RoR) between 5.5°C-6.6°C (42°F-44°F).”
“Once we make our final burner adjustment coming out of the beginning of the roast, we let the RoR take the wheel. This guarantees we’re keeping the overall heat application balanced through the body of the roast, while maintaining an even temperature increase until we reach first crack between 197.7°C-199.4°C (388°F-391°F).”
“To avoid going into first crack with too much momentum, we decrease the burner incrementally, dropping the burner down every -12°C/-9.4°C (10°F/15°F), until we reach first crack. Approaching first crack with a consistently reducing RoR allows us to moderate how much moisture we remove before the coffee really gets rolling during post-crack.”
“Once first crack begins, we dramatically reduce heat to help with acid development post-crack. A secondary benefit to this is it allows us to maintain an even temperature throughout the post-crack development phase. With the Duromina we’re shooting for a drop temperature of about 203°C-204°C (398°F-400°F).”
“Overall roast time for this coffee maxes out around 11:00 minutes at about 15.1K (33.2lbs). The high elevation of Ethiopians calls for an even but higher heat application through the roast helping to maintain acidity while balancing out sweetness and clarity through and through!”
The water:
Rachel Apple, Quality Control Manager for George Howell Coffee Company, has been kind enough to share with us the brew water recipe they use. Which is super simple, just mix together:
- 0.9g Magnesium Sulfate
- 0.08 Potassium Bicarbonate (not baking soda, or Sodium Bicarbonate)
- 1 gallon RO water (or distilled / deionised / pure water)
Please note:
- The Magnesium Sulfate used for this recipe is MgSO4 anhydrous, not Epsom Salts, the Heptahydrate.
- Potassium Bicarbonate is not baking soda, or Sodium Bicarbonate.
- Both Magnesium Sulfate anhydrous and Potassium Bicarbonate can easily be bought from
If you’ve made your own concentrates following our guide here, using these to mimic this recipe you’ll need:
- 24.4g Mg concentrate
- 19.5g Buffer concentrate
- 956.1g DI water
Just divide all three figures by 4 if you’d like a smaller 250g amount of brew water. This isn’t an exact replication of the George Howell recipe, but it’s pretty close.
Brew Guide:
Rachel not only gave us a water recipe, she’s also given us a very cool Kalita Wave 185 recipe. This uses a 1:16.36 ratio, with 22g coffee and 360g total water.