The Science of Coffee Roasting

Coffee roasting is where science and art converge to transform humble green coffee beans into the aromatic, flavorful beans we know and love. At BREWZ Coffee, we take roasting seriously, understanding that it's one of the most crucial steps in developing the character of your cup.

The Transformation Process

Green coffee beans are soft, with a grassy smell and little to no taste. The roasting process applies heat to these beans, triggering a series of chemical reactions that develop flavor, aroma, and color. This transformation is known as the Maillard reaction—the same process that gives browned food its distinctive flavor.

Stages of Roasting

1. Drying Phase (0-4 minutes)

When green beans enter the roaster, they contain about 10-12% moisture. The initial stage of roasting involves drying this moisture out. During this phase, beans turn from green to yellow and develop a hay-like smell.

2. First Crack (6-8 minutes)

As internal bean temperature reaches around 196°C (385°F), the beans undergo "first crack"—an audible cracking sound as water vapor and carbon dioxide break through the bean structure. This marks the beginning of actual roasting, where sugars start to caramelize and oils begin developing.

3. Development Phase (8-12 minutes)

After first crack, the roaster carefully controls heat to develop desired flavor characteristics. This is where the roaster's skill becomes crucial—balancing time and temperature to highlight the bean's natural qualities.

4. Second Crack (12-15 minutes)

If roasting continues, beans reach "second crack" at around 224°C (435°F). This represents a more intense roasting level where oils migrate to the bean surface, creating darker roasts with bolder, less acidic flavors.

Roast Levels and Flavor Profiles

Light Roasts

Stopped before or just as first crack begins. These roasts preserve the bean's original character, featuring:

• Higher acidity
• Pronounced origin characteristics
• Floral, fruit, and citrus notes
• Higher caffeine content

Medium Roasts

Developed through first crack but stopped before second crack. These balanced roasts offer:

• Moderate acidity
• More body than light roasts
• Caramel sweetness
• Balanced flavor profile

Dark Roasts

Developed through or beyond second crack. These intense roasts feature:

• Low acidity
• Bold, rich flavors
• Chocolate, nutty, and spicy notes
• Pronounced bitterness

The Art of Profiling

Modern coffee roasting involves creating detailed "profiles"—precise recipes that specify time, temperature, and airflow throughout the roasting process. Master roasters develop these profiles to highlight the unique characteristics of each coffee origin and variety.

At BREWZ Coffee, we roast in small batches to ensure quality and freshness. Our roasting philosophy balances respecting the bean's inherent qualities while developing optimal flavor through careful profiling. Next time you enjoy our coffee, take a moment to appreciate the science and craftsmanship that went into transforming those beans from their humble green beginnings to your delicious cup.