Dive Deep into Coffee Roasting:

Techniques, Tips & Trends for 2023

Coffee roasting is a crucial step in creating your favorite morning brew. 

The process is responsible for everything you love about a great cup of java, since it brings out the unique flavors and aromas associated with coffee. 

So, if you’re unfamiliar with the roasting process or just want some simple tips on improving your own coffee, you’re in the right place. 

This article dives into the various roasting profiles and techniques that determine the taste, acidity, and complexity of your coffee. You’ll learn more about why we roast, different roasting profiles, as well as tips and techniques. 


Let’s go!

Key Takeaways

  • Coffee roasting is essential for developing the flavors and aromas of green coffee beans
  • Different roasting profiles and techniques impact the taste and complexity of the final product
  • The article covers various aspects of coffee roasting, including the process, profiles, and techniques

The Coffee Roasting Process

When you start roasting coffee, you begin with green coffee beans. 

The roasting process transforms the color of these beans from green to brown. 

The process involves several stages, which help develop the aroma and flavors locked inside the beans. 

Let's dive into these stages, shall we?

The Drying Stage

As you turn on the roaster, the first thing you'll do is pre-heat it. Then, you'll add the green coffee beans. The initial stage, the drying stage, helps eliminate the moisture from the beans. During this stage, the beans will change color, shifting from green to a more yellowish hue.

The Browning Stage

After the drying stage comes the browning stage. This is where the magic starts to happen. The Maillard reaction occurs - a chemical reaction between amino acids and reducing sugars, giving the beans their brown color and toasted aroma. Later in this stage, caramelization and Strecker degradation also happen, contributing to the beans' flavor and fragrance.

First Crack

Soon enough, you'll witness the first crack. This stage is marked by a distinct cracking sound, similar to popcorn popping. The beans develop their first flavors and aromas, indicating a light roast. The beans will swell and double in size, shedding their chaff—a thin skin layer.

Development Stage

Following the first crack, the beans enter the development stage. The roast continues to progress, and the beans darken in color. It's essential to pay close attention to the roast during this stage as the flavors become more nuanced and complex, transitioning from a light roast to a medium roast.

Second Crack

At the second crack, the beans' structure begins to break down, releasing oils to the surface. You'll hear another cracking sound, this time quieter and more subtle than the first crack. The beans are now entering the dark roast territory. Be cautious, as roasting past this point can risk over-roasting and losing the beans' distinctive flavors.

Cooling Stage

Finally, you'll reach the cooling stage. It's crucial to cool down the beans as quickly as possible to halt the roasting process. This helps preserve the desired roast level and prevents the beans from continuing to roast due to residual heat.

Why We Roast (And What Happens When We Do)

Roasting is pivotal in shaping coffee's flavors and aromas. 

Green beans, initially lacking roasted coffee traits, transform during roasting due to reactions like the Maillard reaction, which alters color, flavor, and nutritional content. 

Roasting improves sweetness, body, and solubility. It also reduces acidity, attributed to the creation of flavor compounds and the reduction of chlorogenic acids. And it releases gases, enhancing the coffee's aroma and taste. 

Yet, roasting can diminish bean freshness and authenticity, with over-roasting introducing burnt flavors.

Roast types influence taste:

  • Light roasts maintain original flavors and acidity but may lack body; ideal for floral coffees like Ethiopian varieties.
  • Medium roasts balance origin and roast flavors, suitable for fruity coffees like Colombian beans.
  • Dark roasts prioritize roast flavors, ideal for robust coffees like Indonesian beans.

In essence, roasting is key to unlocking coffee flavors, with each roast catering to varying taste.

Why We Roast (And What Happens When We Do)

A roasting profile is a set of parameters that define how coffee should be roasted to achieve consistent and quality results. 

It takes into account factors such as:

  • Bean type
  • Roast level
  • Roast duration
  • Roast development
  • Roast curve

Let's dive into these factors and explore examples of different roasting profiles.

Bean type refers to the origin, variety, and processing method of the coffee beans. Each type may require different roasting profiles to bring out its unique flavor characteristics.

Roast level generally ranges from light to dark and influences the taste of the coffee. Lighter roasts highlight acidity and complexity, while darker roasts have more body and less acidity.

Roast duration is the total time it takes to roast the coffee, from start to end. This can impact the flavor and develop certain characteristics in your beans.

Roast development is the percentage of time spent after the first crack, a crucial milestone in the roasting process when the beans start making popping sounds. This stage often determines the desired taste qualities in your coffee.

The roast curve represents the rate of rise of temperature over time during the roasting process. This can affect the overall profile of the coffee.

So, now that you know what a roasting profile is and its key factors, it's time to experiment with your coffee beans! 

Try tweaking these factors to find the perfect flavors that suit your taste buds. 

Just remember that it's all about finding the roasting profile that brings out the best in your chosen coffee beans. 

Coffee Roasting Techniques

Roasting coffee beans can be done at home or commercially using various methods.

Check out our list of the 5 Best Home Coffee Roasters!

Here's a rundown of standard techniques to help you choose the best method for your needs.

Stovetop: Using a skillet or a popcorn popper over a gas or electric stove is a cheap and accessible option for roasting coffee at home. However, this method can be uneven, inconsistent, and messy. To improve your results, use a perforated pan or a wire mesh to allow air circulation; stir constantly; use a thermometer; listen for cracks; cool quickly; and remove chaff.

Oven: Roasting coffee in an electric or gas oven with a baking sheet or a perforated tray is simple, convenient, and allows for a large capacity. The downside is that it can be slow, uneven, and smoky. To get better results, preheat your oven to 230°C, spread the beans in a single layer, shake the tray every few minutes, use a thermometer, listen for cracks, cool quickly, and remove chaff.

Air roaster: These machines blow hot air through the beans, providing a fast, even, clean, and adjustable roasting process. The drawbacks are the expense, noise, and typically small capacity. To make the most of your air roaster, follow the manufacturer's instructions, use a timer, monitor the temperature, listen for cracks, cool quickly, and remove chaff.

Drum roaster: Ideal for commercial roasting, drum roasters rotate the beans in a heated drum, resulting in precise, consistent, large capacity, and customizable roasting. The trade-offs are higher cost, complexity, smokiness, and maintenance requirements. To optimize your drum roasting experience, follow the manufacturer's instructions, use a timer, monitor the temperature and the roast curve, listen for cracks, cool quickly, and remove chaff.

Whichever method you choose, remember to experiment and fine-tune your process to achieve the perfect roast for your taste.

Coffee Roasting Temperature Chart

The coffee roasting process involves several stages where the beans undergo various temperature increases and color changes. 

It's essential to understand these phases to achieve your desired roast level. 

Below is an approximate temperature chart that can serve as a reference point when roasting coffee beans:

Roast Level



Cracking Stage

Light Roast


8-12 minutes

First Crack

Medium Roast


10-15 minutes

First Crack End

Dark Roast


12-18 minutes

Second Crack

Note: This chart should be used as a reference but not as a strict rule, as different beans and roasters may vary.

Before roasting, it's important to preheat your roaster to the desired temperature. 

As the beans heat up, they enter the drying phase, where most moisture evaporates. 

Keep an eye on the color as it transitions from green to yellow. This is known as the yellowing phase, where the beans develop flavors and aromas.

The temperature increase should be gradual and steady throughout the process to avoid burning the beans. Also, rely on your senses and experience to determine the roast level. Use indicators like color, sound, smell, and taste, as beans can vary. Use a stopwatch to track time and monitor the consistency of temperature to avoid any uneven roasts.

Coffee Roasting Tips

So, you want to roast your own coffee? Great! Let's dive into some helpful tips to get you started on your journey to coffee roasting mastery.

Start with high-quality green beans: The key to delicious, fresh coffee starts with sourcing your green beans from a reputable source. Specialty and gourmet coffee beans make all the difference in the final flavor, so don't skimp here.

Store your green beans properly: Keep your beans in a cool, dry, dark place, like a storage container, until you're ready to roast. This ensures peak freshness and flavor.

Roast in small batches: Doing so will not only allow for even heat distribution but also help maintain freshness. This is because coffee beans lose weight and volatile organic compounds after roasting. Plus, smaller batches give you more control over the roasting process.

Experiment with different profiles and techniques: Everyone's taste preferences are unique, and by trying out various roasting methods, you might just discover your perfect cup. Craft each roast with care and attention to the balance of sweetness and acidity.

Keep a log of your roasts: Tracking your roasting experiments will help you refine your skills, identify patterns, and ultimately improve your craft. Note the weight of your beans before and after roasting, as well as any changes in flavor.

Roast in a well-ventilated area: Coffee roasting can produce smoke and odor. Avoid fire hazards and ensure proper airflow during your roasting sessions in a well-ventilated space.

Rest roasted beans: Before diving in to grind and brew your freshly roasted beans, give them at least 24 hours to degas. This allows the beans to release excess carbon dioxide and other compounds, leading to a better-tasting, smoother cup of brewed coffee.


In this article, we delved into coffee roasting, a transformative process that turns green beans into the aromatic beans we relish. 

This craft, influenced by bean type and desired roast level, involves intricate chemical reactions at varying temperatures. 

Mastery requires the right tools, knowledge, and practice. 

So, as you embark on your roasting journey, reflect on your favorite roasts, your personal techniques, and the challenges and joys of the process. 

Happy roasting!

This is a guest post written by Colm O'Regan from ModernoCoffee.

Colm is a self-confessed coffee nut and founder at ModernoCoffee.com

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