What is coffee degassing?

The degassing of coffee refers to the period following the roasting process during which the coffee releases some of the accumulated gases inside it. During the roasting stage, various physical and chemical reactions occur, altering the composition and flavors of the coffee bean. As a result of these reactions, gases, primarily carbon dioxide (CO2), are generated, contributing to the preservation of the bean but also potentially hindering its extraction during coffee preparation.

Degassing is crucial for achieving high-quality coffee, as it allows the gases released during roasting to dissipate, thereby facilitating the extraction of desired flavors and aromas when preparing the beverage. This process can significantly impact the final result in the cup, as the trapped CO2 in the coffee can impede the proper extraction of soluble compounds, affecting the taste and crema of the coffee. The duration of degassing may vary depending on the roasting method and the type of coffee, and it is an essential aspect to ensure an optimal sensory experience when enjoying a freshly brewed cup of coffee.

Why does coffee degassing occur?

To roast coffee, we apply heat to the interior of the roasting drum. This heat is transferred to the beans, increasing their temperature. The moisture (water) present in the green coffee begins to heat up, creating vapor inside and increasing the pressure, facilitating chemical reactions with other components such as sugars, carbohydrates and lipids.

As we reach the final stage of roasting, the beans exceed temperatures of 180º. This phase is recognizable as the beans emit a sound similar to popping corn, commonly known as the first crack. From this moment on, the beans enter the pyrolysis phase, and this is when a higher quantity of gases is produced. Some of these gases are literally trapped in the now porous beans.

How long does it take for coffee to degas?

Freshly roasted coffee has the highest percentage of CO2, but as the days pass, it gradually escapes. After a month and a half or two months, there is practically none left, accelerating the oxidation process.

How long should we wait for proper degassing of coffee?

After 4 to 10 days, the beans reach suitable levels where CO2 no longer compromises the flavor of your coffee.

However, this timeframe is just a guideline because to truly understand how long degassing takes and its impact on our brew, we must consider these factors:

• Bean Type: Each variety and sub-variety has unique genetics and density. It has also been cultivated and processed differently.
• Roasting: The intensity of the roast, the volume the beans reach, or their density.
• Coffee Storage: Ground, whole bean, type of packaging.
• Brewing Method: Espresso, moka, V60, pour-over, French press.