Degassing in Coffee: What Does It Mean?

When it comes to enjoying a delicious cup of coffee, there are many factors that can impact the final taste and quality. One crucial aspect that often goes unnoticed is the degassing process. In the world of coffee, degassing refers to the release of carbon dioxide gas that occurs after roasting the beans. This natural process plays a significant role in the overall flavor and aroma of your cup of joe.

Why Does Degassing Occur?

During the roasting process, coffee beans go through a chemical reaction known as the Maillard reaction. This reaction causes the release of carbon dioxide gas as a byproduct. As the beans cool down and reach room temperature, they continue to emit gas for some time. This degassing period is essential for achieving optimal flavor when brewing your coffee.

The Degassing Timeline

The degassing process typically follows a predictable timeline after the beans have been roasted:

  1. First few hours: Within the first few hours after roasting, the beans release a significant amount of carbon dioxide. This initial burst of gas is often referred to as the “bloom.” The coffee is prone to excessive off-gassing during this stage.
  2. One to seven days: During this period, the degassing process continues at a steady pace. Carbon dioxide slowly dissipates from the beans, and the flavors and aromas begin to develop and stabilize.
  3. One to three weeks: At this stage, degassing begins to slow down, and the coffee reaches its peak flavor. The aromatic compounds that contribute to the aroma become more pronounced and balanced.
  4. Three weeks and beyond: While degassing continues to a lesser extent, the beans have mostly released their carbon dioxide by this point. However, the coffee is still enjoyable and can be brewed, although it may lack the vibrant flavors of fresher coffee.

Factors Influencing Degassing

Several factors can influence the degassing process and the duration it takes for coffee beans to release carbon dioxide:

  • Roast level: Lighter roasts typically degas faster than darker roasts due to the shorter duration of the roasting process.
  • Grind size: Finely ground coffee will degas more quickly than coarsely ground coffee, as the smaller particles provide more surface area for gas to escape.
  • Bean freshness: Freshly roasted beans will off-gas more rapidly compared to older beans that have already degassed to some extent.
  • Packaging: The type of packaging can affect the degassing process. Coffee stored in valve-sealed bags allows for gradual gas release, while non-sealed containers may cause carbon dioxide to build up and stale the beans.
  • Environment: Temperature and humidity can impact the rate of degassing. Higher temperatures and humidity levels can accelerate the process, while low temperatures may slow it down.

Degassing and Brewing

Understanding the degassing process is crucial for achieving the best possible flavor when brewing your coffee:

Degassing Stage Ideal Brewing Time
1 – 7 days Wait a couple of days after roasting before brewing for optimal results. This period allows flavors to develop while excessive off-gassing subsides.
1 – 3 weeks During this stage, the coffee is at its peak flavor. Brew it within this timeframe to enjoy the full range of flavors and aromas.
3 weeks and beyond While the coffee is still perfectly drinkable, it may have lost some of its initial vibrancy. Adjust brewing techniques to account for any flavor changes.

By understanding the degassing timeline and its impact on flavor, you can make informed decisions about when to brew your coffee for the best taste experience.


Degassing is a critical process in coffee that affects the overall flavor and aroma of the final brew. By allowing the coffee beans to degas adequately, you can achieve a more balanced and flavorful cup of coffee. Factors such as roast level, grind size, and packaging all influence the degassing process, and understanding these factors can help you make the most of your coffee beans. So, the next time you prepare a cup of coffee, give a thought to degassing and how it contributes to your enjoyment of this beloved beverage.