Oasis:
TIM (Terroir Intensified Maceration), also known as the terroir-enhanced process, is a method somewhat akin to winemaking or braising. The process involves retaining the fermentation liquid from a previous batch of coffee and using it to ferment the next batch. This liquid contains microorganisms native to the terroir, continuously aiding in the fermentation of each batch and amplifying the flavor impact of the microbes specific to that area.
In coffees processed using this method, we often find a more rounded acidity and a sweetness reminiscent of cascara (coffee cherry tea).
Alo is one of our favorite beans among this year’s purchases. Oasis has been collaborating with Tri-Up Coffee, a green bean supplier, which initiated a partnership with Tamiru in 2021. This project aimed to address the impacts of climate change and global warming. Coffee grown at lower altitudes faces shortened ripening periods, leading to insufficient sucrose content. To counteract this, Tamiru enthusiastically supported the initiative to source higher-altitude coffee. This particular batch focuses on coffee cherries grown at altitudes above 2,500 meters, a height exceeding half the elevation of Taiwan’s Jade Mountain.
Reaching this altitude required overcoming logistical challenges, including transportation across rugged terrain and the need for significant manpower. Coffee cherries harvested at such high altitudes benefit from the cold climate, resulting in longer ripening periods. Additionally, the reduced microbial diversity at these elevations ensures exceptionally clean coffee with higher sweetness. This inspired us to name this premium high-altitude batch “Sky Project.”
As part of the Sky Project, Tamiru further sorted the smallest coffee beans and created the “Pearl Batch” due to their smaller size, which often correlates with greater sweetness. This is the origin of the ALO SKY PROJECT PEARL batch.
74158 Variety
Ethiopian coffee varieties were historically classified as heirloom varieties. To better utilize Ethiopia’s rich genetic coffee diversity and improve the national coffee industry, the Ethiopian government established a dedicated research institution known as the Jimma Agricultural Research Center (JARC). JARC focuses on collecting, identifying, and preserving coffee varieties, while also improving agricultural practices, post-harvest processing techniques, and developing new varieties. Today, the center prioritizes the development of improved coffee varieties.
In 1971, Coffee Berry Disease (CBD) spread across Ethiopia. Initial trials in 1972 used chemical fungicides to prevent the disease. Although these methods were effective, researchers believed the best solution lay in leveraging Ethiopia’s genetic coffee diversity to develop CBD-resistant varieties. Selection efforts began in 1973, with researchers collecting coffee varieties from 19 regions in southwest Ethiopia. These varieties underwent extensive field and laboratory testing.
Ultimately, researchers identified 13 coffee trees from Gera, Metu-Bishari, Washi, and Wush Wush regions with resistance to CBD. In 1974 and 1975, new CBD-resistant varieties were developed. Varieties named with “74” or “75” indicate the year they were first selected and classified, with subsequent numbers serving as their registration codes.
The 74158 variety originated from a mother tree in the Illubabora district of Metu Bishari. JARC officially released this variety in 1979. Due to its resistance to CBD and high yield, 74158 became popular among farmers and is widely cultivated.
Two-Temperature Brewing Method
Grind Size:
Medium grind, 800–900 μm
Grinder Settings & RPM:
• EK43: 7:30 o’clock direction
• Option-O: Setting 7.5, speed 5
• Fellow Ode: Setting 3.2
• Xiao Feima (DF64): Setting 3.5
• Comandante C40: 25 clicks
Water Specifications:
• TDS: 40–60 ppm
• Two water temperatures: 92°C & 65°C
Brewing Ratios:
• Coffee-to-water ratio (grounds-to-total water): 1:14
• Coffee-to-liquid ratio (grounds-to-brewed coffee weight): 1:11
Brewing Example
• Coffee grounds: 15 g
• Total water: 210 g
• Brewed coffee weight: 165 g
• Pour sequence (3:4:5:2)
1. First Pour (00:00): 45 g of water at 65°C
2. Second Pour (00:20): Add water to 105 g total at 92°C
3. Third Pour (00:40): Add water to 180 g total at 92°C
4. Fourth Pour (01:00): Add water to 210 g total at 65°C
Stop the extraction when the brewed coffee weight reaches 165 g.
Adjustments for Astringency
1. Shorten the coffee-to-liquid ratio (reduce the brewed coffee weight).
2. Stop the extraction earlier.
3. Use a bypass method to adjust the final concentration.
Single-Temperature Brewing Method
Grind Size:
Medium grind, 800–900 μm
Grinder Settings & RPM:
• EK43: 7:30 o’clock direction
• Option-O: Setting 7.5, speed 5
• Fellow Ode: Setting 3.2
• Xiao Feima (DF64): Setting 3.5
• Comandante C40: 25 clicks
Water Specifications:
• TDS: 40–60 ppm
• Single water temperature: 90°C
Brewing Ratios:
• Coffee-to-water ratio (grounds-to-total water): 1:14
• Coffee-to-liquid ratio (grounds-to-brewed coffee weight): 1:11
Brewing Example
• Coffee Grounds: 15 g
• Total Water: 210 g
• Brewed Coffee Weight: 165 g
Pouring Steps:
1. First Pour (00:00): Add 70 g of water at 90°C.
2. Second Pour (00:20): Continue pouring until reaching 140 g total at 90°C.
3. Third Pour (00:50): Continue pouring until reaching 210 g total at 90°C.
Extraction Process:
• Stop extraction when the brewed coffee weight reaches 165 g.
• Add 10 g of hot water (bypass) to adjust concentration.
Adjustments for Astringency:
1. Shorten the coffee-to-liquid ratio (reduce the brewed coffee weight).
2. Stop extraction earlier to avoid over-extraction.
3. Use the bypass method to adjust the final concentration.