What is Coffee Roasting

What is Coffee Roasting?

Curious about coffee roasting? It's a captivating subject for coffee lovers, and it's easy to see why. This process takes a simple coffee cherry and turns it into the diverse and flavorful beans we grind, brew, and savor daily. Variations in the roasting process can also bring out different flavors in the same bean! In this article, we'll explore why understanding coffee roasting is crucial for brewing that perfect cup of coffee you love.

The Five Distinct Stages
Raw coffee cherries

The Five Stages

Once harvested, coffee beans are considered "green," retaining their raw, soft form. Roasting is the vital process that transforms them into the familiar browned beans, slightly cracked, and exuding that irresistible coffee aroma.

Roasting aims to bring the beans to a precise level of development through controlled heating. While the exact conditions vary depending on the coffee type, the roasting journey typically encompasses five distinct stages:

1. Drying or Yellowing

This initial stage hinges on the beans' initial moisture content. Here, the beans transition to a yellow hue, emitting a hay-like aroma.

2. Maillard Reaction

As the beans start to "brown," this reaction sets off the formation of various chemical compounds, releasing aromatic notes into the air.

3. First Crack

At this juncture, the focus shifts from heating the outer shell to the heat buildup within the bean. The pressure from evaporation and heat causes the bean to audibly crack, signifying its breakdown from the inside out.

4. Second Crack

Darker roasts progress to a second cracking phase, indicating that the beans are approaching complete breakdown.

5. Carbonization

The final stage, characterized by the beans' full breakdown, which is to be avoided to maintain optimal flavor and quality.


Freshly roasted coffee

Creating Different Roast Levels

As the roasting time extends, different roast levels are achieved, offering a spectrum of flavors and characteristics. Generally, there are four main types of roasts: light, medium, medium-dark, and dark. Each level brings its own unique qualities, and the "perfect" roast is ultimately a matter of personal preference. Here's a brief overview of the different roast types:

Light Roasts

Light roast coffee boasts a pale brown color and a surface free of oil. These roasts reach internal temperatures of 176-204 °C, just barely hitting the first crack during roasting. They are often referred to as Light City, Half City, or Cinnamon roasts. Light roasts are known for their bright acidity, pronounced fruity and floral notes, and a crisp, clean finish.

Medium Roasts

Medium roast coffee features a medium brown color and a non-oily surface. With internal temperatures peaking at 204-221 °C, these roasts typically pass the first crack but stop short of the second. They are also known as City, American, or Breakfast roasts. Medium roasts offer a balanced flavor profile with moderate acidity, enhanced sweetness, and a fuller body compared to light roasts.

Medium-Dark Roasts

Medium-dark roasts exhibit deeper brown hues than medium roasts and may display some oil on the surface. These roasts reach internal temperatures of 225-230 °C, occurring during or just after the second crack. They are often referred to as Full City roasts. Medium-dark roasts feature a richer flavor profile with prominent caramelization, bittersweet chocolate notes, and a lingering finish.

Dark Roasts

Dark roast coffees are roasted beyond the second crack, resulting in a rich, dark color and an oily surface. With peak internal temperatures around 240 °C, these roasts push the bean to its limits without compromising its integrity. They are known by various names such as High, Continental, New Orleans, European, Espresso, Viennese, Italian, and French roasts. Dark roasts offer bold, smoky flavors with low acidity, intense bitterness, and a robust body.

Its Role in Coffee Extraction
Dark roast coffee beans with their oily sheen

Impact on Coffee Extraction

Roasting is the magic that unlocks the hidden flavors and aromas tucked away inside raw, green coffee beans. In their unroasted state, these beans possess a grassy scent and lack any discernible taste. When subjected to the roasting process, however, a myriad of chemical changes happen within the bean.

The sugars, starches, fats, and oils within the bean undergo a transformation—they're emulsified, caramelized, and released under high heat. Once they reach the perfect balance, the beans are swiftly cooled to halt the roasting process. This process is what extracts the sweetness, bitterness, and unique characteristics inherent to the bean's region and variety.

Increases Solubility

Roasting not only enhances the flavors and aromas but also boosts the solubility of the coffee beans. With each stage of the roast, the beans become more soluble in water.

Why does solubility matter? Well, it's the cornerstone of the brewing experience. The degree of solubility in a specific roast determines how effectively the coffee's attributes are extracted. Some coffees shine with higher solubility, while others thrive with less. Solubility also dictates the optimal brewing conditions, including water temperature, brew time, and grind size.

Evolves Flavor Compounds

As mentioned earlier, roasting leads to the breakdown of compounds within the coffee bean. This breakdown not only impacts solubility but also influences the flavor progression of the coffee. As the roast advances from light to dark, the bean's flavor profile becomes more or less pronounced.

Light roasts often boast crisp acidity with citrus, malic acid, and apple-like notes, along with a gentle body. Medium roasts develop moderate acidity, a well-balanced body, and hints of nuts and chocolate. Darker roasts offer a heavier body, deeper flavors, and rich caramel sweetness.

Choosing the perfect roast level hinges on factors like the bean's origin, variety, and more. Roasters must skillfully navigate the heating process and stop at just the right moment to showcase the coffee's natural flavor profile.

Progression of Flavor Compounds
The coffee roast heavily influences the flavor notes of your brew


Coffee roasting stands as a cornerstone of coffee quality and taste. It's a meticulous craft, evolving with each batch, that turns ordinary green beans into the aromatic and flavorful coffee we love.

Starting from humble beginnings in a home kitchen, Plain Sight has honed our roasting process into the artistry it is today. We're dedicated to ongoing training and refinement to craft our specialty coffee products. Explore our selection here to experience the fruits of our labor!

Edited by Natalie Ann Unson
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