Why Do You Need Degassing Your Coffee?

You may be or may be not familiar with the term “degas” when it comes to coffee. Degassing refers to the process of allowing freshly roasted coffee beans to release excess carbon dioxide (CO2) before brewing. In this post, we’ll explore the definition of degassing, how it differs between light roast and dark roast coffee, and the impact of degassed coffee on extraction. Additionally, we’ll discuss alternative methods to speed up the process for time-conscious baristas.

Definition of Degassing: What is it?

When coffee beans are roasted, they release CO2 as a natural byproduct of the chemical reactions occurring within them. This CO2 becomes trapped within the beans and forms small bubbles. The gas interferes the contact between the coffee grounds and the water during extraction, causing inconsistency of your brew. Degassing involves allowing these trapped gases to escape, resulting in a more balanced and optimal coffee flavour.

How Do You Degas Your Coffee?

You can simply leave the bags of coffee sealed and store them in a cool and dry place for a period of time. This can vary from few days to 2~3 weeks and depends on the several factors. But if time is limited, baristas can employ alternative methods to expedite the degassing process:

Vacuum Sealing: Using a vacuum sealer, you can create a low-pressure environment that promotes faster CO2 release from the beans. This method can significantly reduce degassing time.

Forced Degassing: Some specialty coffee professionals use machines specifically designed to remove CO2 from coffee beans. These machines apply pressure changes and agitation to accelerate the degassing process.

Degassing Time Differs

Several factors can influence the rate at which gases are released. Here are some key factors that can affect the time for gases to release:

Roast Level: The degree of roast affects the degassing process. Darker roasts typically degas more slowly compared to lighter roasts. This is because the extended roasting time reduces the overall gas content in the coffee beans.

Temperature: Higher temperatures accelerate the process. In warmer temperatures, the heat increases the kinetic energy of gas molecules, facilitating their escape from the beans. This leads to a faster release of gases, including carbon dioxide (CO2), during degassing. It is more likely for coffee to release gases faster during summer than winter.

Moisture Level: Coffee beans are hygroscopic, meaning they can absorb moisture from the surrounding environment. The moisture absorption can slow down the degassing process because it disturbs the gas to escape from the beans.

Storage Conditions: The way coffee is stored can affect its degassing rate. Coffee stored in airtight containers will experience slower gas-releasing compared to coffee stored in more permeable containers or bags. Exposure to air facilitates the release of gases.

Extraction Comparison: The Fresh vs The Degassed

Degassing plays a crucial role in achieving consistent and balanced coffee extraction. Here are some comparisons between extracting degassed coffee and freshly roasted coffee:

Flavour Development: Freshly roasted coffee may have uneven flavour extraction due to the presence of excess CO2. Degassed coffee allows for a smoother and more balanced flavour profile, as the release of CO2 reduces interference with the extraction process.

Consistency: Degassed coffee results in more consistent brewing. Excess CO2 in freshly roasted beans can cause irregular bubbling and uneven extraction, leading to inconsistent flavours. Degassed coffee, on the other hand, offers more uniform brewing behaviour, resulting in a reliable extraction.

Conclusion

Understanding the concept of degassing is essential for baristas seeking to extract the best flavours from their coffee beans. Light roast and dark roast coffee differ in degassing time due to moisture content, density, and chemical reactions. Degassed coffee offers improved flavour development and consistency during extraction. If time is a concern, alternative methods such as vacuum sealing and forced degassing can help expedite the process. Embracing the degassing process ensures a more enjoyable coffee experience for both baristas and coffee enthusiasts alike.