What Is Coffee Degassing?

During and after roasting, many processes and chemical reactions take place within the cellular structure of the coffee beans.

One of these is known as degassing. But what is coffee degassing? Let’s take a look, shall we?

What’s It All About?

Degassing is the release of gases from roasted beans. During roasting, lots of gases are produced. One of these gasses is carbon dioxide; which your coffee shouldn’t be full of, but it can be useful in small doses.


coffee in a cooling bin


The gases that form during roasting will naturally escape in the first few days after roasting. Drinking coffee within its first few days? During that time, you may notice small bubbles form in your coffee. These bubbles are nothing to worry about. Too much carbon dioxide left within the coffee, however, can result in an uneven extraction and can, therefore, cause flavours and aromas to become bland. To avoid this, here at Two Chimps Coffee we inform you of the roast date on every bag so you can see when your coffee was freshly roasted and therefore plan accordingly.

Where Does The Carbon Dioxide Come From?

As mentioned, during roasting, many chemical reactions occur. As the beans begin to turn from green to yellow, to brown, water vapour and carbon dioxide are created. At first crack, this build of gases creates so much pressure that the bean’s cell wall is broken as they escape.


Coffee spinning in roaster drum

Is Carbon Dioxide in Coffee Good or Bad?

Carbon dioxide plays an important role in overall coffee quality. The freshness of a coffee can be determined by the level of carbon dioxide it has. As mentioned, it can also have a big impact on the extraction of a coffee.

If coffee has degassed too much, the flavours won’t be as vibrant as anticipated, and generally will be quite bland. You may find yourself having to use more coffee than normal to try and get more flavour from it.

Making espresso? On the other hand, if you haven’t given the coffee long enough to degas, it may take longer to pull that shot of espresso. This is because the gases from the coffees impede the water and make extraction much harder.

So in short, too much carbon dioxide will make extraction harder and not enough will cause produce bland flavours.


a shot of espresso pouring into a mug

So How Long Should It Be Left?

Generally, anytime between 3 days to two weeks is the best time to brew your coffee. Factors such as processing methods and roast profile, however, do affect this time also.

As a general rule, when it comes to processing methods, natural coffees take slightly longer to go through the coffee degassing process, compared to washed coffees. What is the difference? Check out the different ways of processing and drying coffee.

If a coffee has been roasted darker, it will need less time to degas. Because it has spent longer in the roaster, more cracks form allowing the carbon dioxide to escape quicker. Lighter roasted beans are more intact, meaning they will need slightly longer for the coffee degassing process to be completed.


coffee in an orange mug with a kettle and tin

Keeping It Fresh

Our ethos at Two Chimps Coffee is fresh is best. We have a number of ways to keep your coffee super fresh.

Firstly, we roast multiple times each week, by hand and in small batches. This assures that your coffee is always super fresh to start with.

When completing orders, the very last thing we do is grind your coffee. This means that the time between your coffee being ground and it reaching you is as short as possible. Ground coffee will lose its freshness slightly quicker, so we want to give you as much time as possible to enjoy it!


Aeropress with coffee on a spoon


On the back of your coffee bag, you will find a one-way valve. This allows the carbon dioxide to continue to escape however, it stops any oxygen from getting in. Oxygen can suck the freshness out of coffee and leave it tasting bland.

When you get a minute, grab your bag of coffee to see the one-way valve. Don’t have a bag of coffee, or have one without a valve? Don’t worry, head over to our shop today. Awesome coffee is just a few clicks away, and it comes with FREE postage!


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