Yirgacheffe Coffee Bean Roasting Levels: Flavor Differences Between Light and Dark Roasts

Roasting is one of the most captivating stages in the coffee industry. Green coffee beans have almost no discernible flavor and taste rather unpleasantly vegetal when consumed directly. So what kind of roasting process can transform these seemingly ordinary beans into something remarkable? FrontStreet Coffee will guide you through the mystery behind coffee roasting using Yirgacheffe as an example.

To put it simply, when we observe how dark the final color of coffee beans is and how long the roasting took, then easily conclude that a certain coffee is light or dark roast, we're often being one-sided. This is because the coffee might have been fast-roasted or slow-roasted, and different roasting speeds (fast or slow) produce completely different flavor profiles, even when the coffee beans appear similar in color.

Coffee undergoes various chemical reactions during roasting. Many of these reactions cause the beans to lose weight and moisture content. Slow roasting (14-20 minutes) results in a higher weight loss ratio (about 16%-18%), while fast roasting can be completed in as little as 90 seconds. For a relatively expensive coffee, slow roasting often presents better flavors.

The Three Key Elements of Coffee Flavor

During roasting, three elements determine the final flavor of coffee: acidity, sweetness, and bitterness. Generally, the longer the overall roasting time, the less acidity remains, while bitterness increases with extended roasting time. This is why darker roasted coffee beans tend to be more bitter.

There are many critical stages in roasting, and what we call different roast profiles depends on how quickly a batch of coffee beans passes through these stages. Many roasters carefully document each roast to ensure they can replicate it with minimal variations in temperature and time.

The Two Main Stages of Coffee Roasting

During roasting, steam and carbon dioxide are produced as temperature rises. These gases increase the internal pressure of the coffee beans, causing them to expand. When the expansion reaches a certain point, the beans produce a popping sound, similar to popcorn. This is what we call the first crack. The first crack refers to the first rupture of the coffee beans' internal cells, while the second crack refers to the second rupture. Since coffee beans continuously produce gas during roasting, the beans continue to expand, creating sounds similar to those during the first crack.

Light Roast

Light roast refers to coffee beans roasted from the middle of the first crack to just after the first crack ends. At this stage, enzymatic activity and the early Maillard reaction occur, and the organic acids in the beans haven't been completely broken down yet. Therefore, the acidity is more prominent while bitterness is barely noticeable, making it ideal for those who enjoy acidic coffee.

The flavors at this stage are predominantly floral, fruity, with notes of cinnamon and grains.

Medium Roast

Medium roast typically refers to the period from the end of the first crack to before the second crack. At this stage, caramelization occurs and reacts more with the Maillard process. Although there are still acidic aromas, they are significantly weaker than in light roasts. The acidity and bitterness are more balanced, making the sweet flavors more prominent and very smooth, with notes mainly of caramel and chocolate.

This roast level often allows specialty coffee to showcase its best characteristics and is also the most commonly used roast level at FrontStreet Coffee.

What Roast Level is Suitable for Ethiopian Yirgacheffe?

Taking washed Yirgacheffe as an example, if you enjoy rich floral aromas and abundant fruit acidity, FrontStreet Coffee recommends using light or medium roast.

Natural processed Yirgacheffe possesses most of the advantages of washed processing, but with additional fruity aromas and less pronounced acidity compared to washed Yirgacheffe.

Take FrontStreet Coffee's natural processed Yirgacheffe "Red Cherry" as an example. We chose a medium-light roast, which often brings out the best characteristics of these beans while maintaining their texture and unique fermented wine aroma.

FrontStreet Coffee's Brewing Parameters:

Filter: V60 dripper
Water temperature: 90-91°C
Coffee amount: 15g
Water-to-coffee ratio: 1:15
Grind size: Medium-fine (80% passes through China standard #20 sieve)
Brewing method: Poured over in stages

Using a three-stage pouring method: start timing with the first pour to 30g and let it bloom for 30 seconds. Then begin the second pour, using a small stream to reach 125g. Wait for the coffee bed to drop halfway before the third pour, again using a small stream to reach 225g. Wait for the extraction to complete, with a total time controlled around 2 minutes.

Flavor notes: Berries, lemon, fermented fruit aroma, strawberry.

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Important Notice :

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Tel:020 38364473