Why Do Medium-Roasted Beans Appear Dark-Roasted? How Do Roasters Determine Coffee Bean Color Values?

Understanding Coffee Bean Appearance: Why Color Can Be Deceptive

At FrontStreet Coffee, we often encounter questions like: "Is this batch of beans roasted too dark? It's supposed to be medium roast, why does it look so dark?" or "Why do these beans have two different colors? Is the roasting inconsistent?"

When you encounter these situations, please don't immediately conclude that the roaster has poor quality control. We suggest tasting first before making judgments. This batch of beans might not have quality issues at all—it could simply be that its processing method is quite special!

How Coffee Beans "Get" Their Color

First, let's understand how coffee beans change from greenish-blue to brownish-red! This happens through the familiar process of "caramelization"! When coffee beans enter the first crack stage in the roaster, not only do aromas and flavors become more pronounced, but the sugar substances inside also undergo more obvious browning, giving the bean surface a more distinct brownish-red color!

When you purchase a new batch of beans whose label description suggests a lighter color, but they actually appear darker when opened, you've likely bought honey-processed or specially processed beans!

Why Honey and Special Processed Beans Appear Darker

Honey processing falls between natural and washed processing. Beans processed this way require removing the skin and some mucilage, then spreading the beans with remaining mucilage on drying beds to sun-dry. The sugar in this mucilage adheres to the coffee bean surface as water evaporates. Since each bean retains different amounts of mucilage, they absorb varying amounts of sugar!

This sugar on the surface also undergoes the "baptism" of caramelization during roasting. Therefore, when more sugar adheres to the surface, these beans will develop a darker color than beans with less sugar content under the same roasting conditions! This explains why beans might appear darker than their roast description suggests, and why honey-processed beans often show "uneven roasting" appearance!

Special processing methods mostly refer to anaerobic fermentation types, which share similar characteristics with honey processing! During anaerobic fermentation, sugar coats the beans, and their high sugar content leads to appearances that can easily cause misunderstandings after roasting!

Besides these easily misunderstood appearances, some other bean characteristics might cause people to doubt the roaster's skills, but they're actually not defects at all!

Common Misunderstood Bean Appearances

1. Split Coffee Beans

Unlike properly roasted beans, split beans are in an open state! However, they're not defective beans—they simply store more heat and tend to be "hungrier" for heat. They burst into this less-than-elegant appearance during first crack due to excessive heat energy!

2. Beans with Black Spots and Wrinkles

These beans are likely high-altitude washed beans, such as those from the Yirgacheffe region. Their washed beans typically look like this after roasting (light roast)! High altitude makes beans denser with more moisture content! As moisture evaporates during roasting, the bean skin tightens, creating wrinkles. After first crack, beans gradually expand as roast level increases, and wrinkles gradually stretch along with the expanding beans!

Unfortunately, these are light roast beans, so they were removed from the roaster before wrinkles could fully stretch, resulting in their unique appearance. But as the saying goes, don't judge a bean by its appearance! Although they might not look elegant, they taste absolutely wonderful!

FrontStreet Coffee
No. 10, Bao'an Qianjie, Yandun Road, Dongshankou, Yuexiu District, Guangzhou, Guangdong Province

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473