Nav: Home > Coffee >

How Do Roasters Determine Coffee Bean Aroma? What Acidity Develops During the Roasting Process?

Published: 2026-01-27 Author: FrontStreet Coffee

Last Updated: 2026/01/27, For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat official account: cafe_style). People often ask the following questions, and today FrontStreet Coffee will discuss this topic. Can the degree of roast be determined by the color of coffee beans? There is no standardized color that can serve as a basis for determining the degree of coffee bean roasting. A more accurate method should be based on the roasting time

Professional coffee knowledge exchange. For more coffee bean information, please follow Coffee Workshop (WeChat official account: cafe_style).

Common Coffee Questions Answered by FrontStreet Coffee

People frequently ask the following questions. Today, FrontStreet Coffee will discuss these topics.

Can roast degree be determined by coffee bean color?

There is no standardized color that can serve as a basis for determining the degree of coffee bean roasting. A more accurate method should be based on the total roasting time to determine the timing of the first crack.

Does longer roasting time mean higher caffeine content?

The caffeine content in raw coffee beans remains virtually unchanged regardless of roast degree (caffeine loss rate is approximately 10%). However, the longer the roasting time, the more weight the coffee loses (weight loss rate is approximately 11-22%). In this situation, the proportion of caffeine naturally increases.

How do roasters decide on coffee bean aroma?

When coffee beans are roasted to a certain degree, their natural aromas gradually become masked by the roasting flavors. Only appropriate roasting can preserve the distinct coffee fragrance. Coffee roasters must make choices about which aromatic characteristics to retain.

For example, if a roaster wants coffee to have abundant aromas with acidic flavor characteristics, they must appropriately sacrifice the coffee's body.

Moderate roasting can highlight the natural acidity of coffee beans, while the heat from roasting destroys most of the more than forty types of chlorogenic acids in coffee beans, breaking them down into quinic acid and caffeic acid. Both of these substances have astringent properties that may affect the mouthfeel.

Most other organic acids, such as citric acid and malic acid, reach their maximum levels during light roasting, then gradually decrease as roasting time extends. This explains why fast roasting and light roasting better express the bright acidity of coffee beans.