Coffee Degassing: Why And What Does It Mean?

Degassing is the process of gas emission after roasting coffee beans when you roast coffee, a large amount of carbon dioxide and gas will be generated inside the coffee beans.

A lot of gas will be released in the first few days after roasting. The problem is that these gas will release small bubbles when you brew, which will affect your coffee. These bubbles will destroy the contact between coffee powder and water, resulting in flavor and flavor. The extraction of aroma substances is uneven.

In other words, if you brew freshly roasted coffee, these gases will have a negative impact on the flavor of your coffee.

For this reason, it is better to wait a few days after roasting before making coffee. The period of carbon dioxide emission and chemical changes is called degassing.

When the coffee is roasted between the first burst and the second burst, the coffee beans will undergo a degradation reaction. When it reaches about 220°C, the sugar will be broken down into several different compounds, including carbon dioxide. The coffee beans start to turn brown because the water loss will also decrease.

The degradation reaction is the most important chemical reaction at the end of roasting because when it is degraded, it will be converted into sugar. When energy is released, gas is produced.

But the carbon dioxide in coffee beans is not a bad thing, and it plays an important role in the quality of coffee. Carbon dioxide is an important indicator of coffee freshness and plays an important role in shelf life and packaging. It affects the process of coffee extraction, the formation of espresso crema and may also affect the sensory flavor characteristics of coffee.

When the coffee beans are exhausted too much, the flavor will be less pronounced. The secret is that the degassing time should be moderate, instead of waiting until the beans are left for too long to become old. The gas still released is an indicator of the freshness of the coffee beans, but when the coffee is too fresh, it will prevent the coffee powder from being completely extracted.

If you use coffee beans that are not degassing long enough, it may take longer to extract a dose of espresso because gas will hinder the flow of water. These gases contribute to crema formation because bubbles are generated during extraction, but the flavor is also less than ideal because the gas will also interrupt the extraction process.

The venting of the coffee is important because it will make the coffee flavor brighter.

For example, using Behmor 1600 Plus to Guatemalan roast coffee will have a rubbery taste after 72 hours of roasting. Still, after 96 hours, the chocolate flavor of the coffee will become obvious, and the flavor of the coffee will frame. The established ones are more complete.

Degassing will disperse the carbon dioxide produced during the roasting process of coffee. Still, we don't want these gases to disappear completely, but the gas content of the coffee is just right when we want to drink, and the proper content of carbon dioxide will make the coffee taste less bland.

However, how long it takes to leave after roasting depends on many factors. Usually, three days to two weeks or three weeks after roasting coffee beans are suitable for brewing. However, the difference of each type of coffee will also make the required degassing time different. , Brewing method, processing method, the roasting degree will affect the length of the degassing time.

The harvesting and washing procedures of coffee berries will always be different, the drying procedures will be different, and the water quality will be different, so I think this is why the degassing time will also be different. Coffee beans also have different sizes, so the amount of water and gas contained in them will be different.

If the coffee beans are used for hand brewing or French press, they can be used up as soon as possible a few days after roasting because coffee and water have a long contact time, so there is no need to degassing too much.

On the contrary, when we want to brew espresso because the brewing time is very short (usually only more than 20 seconds), it means that bubbles will affect the extraction result to a greater extent.

Espresso coffee is very special. It needs a longer rest time. You will not see someone taking the freshly roasted coffee directly to extract and concentrate. The key is to stand still and degas so that the coffee can develop its flavor when brewing.

If it is for extracting and concentrating beans, we usually hope that the coffee will be used five to seven days after roasting to be easier to extract the coffee, and the time for hand brewing will be shorter.

The three main coffee processing methods: washing, sun drying, and honey processing will also affect the air degassing of coffee. We believe that sun-dried coffee beans need a longer degassing period than washing.

If sun-dried beans are cooked within three to five days after roasting, they often still have the problem of being too fresh. Sun-dried beans need more time to degas.

Dark roasted coffee will accelerate the degassing of coffee beans because coffee beans have a higher degree of degradation. Sugar will be converted in greater amounts, and more small cracks will cause more carbon dioxide to be released.

Light roasted coffee beans are closer to the unroasted state, and this means that lighter roasted coffee beans need more time to degas.

If the coffee beans are roasted unevenly, it may lead to the uneven development of the coffee beans; the difference in degradation time will affect the degree of development of the coffee beans, which in turn affects the rate of degassing of the cooked beans.

How do you ensure that the coffee you drink has been degassed in the "correct" amount?

It is very helpful to record the actual roasting date, especially when roasted beans are large.

The coffee is usually bagged 20 minutes to an hour after roasting, but the premise is that the coffee bean bag has a vent valve. When customers get our coffee, it is usually three days after roasting. The degassing valve is to allows the coffee beans to vent normally during transportation. If there is a collision, it can prevent the bean bag from bursting.

Some roasters may not have nitrogen-filling equipment, but there will be no problems with large amounts of roasting or long-distance transportation.

If the coffee starts to lose its flavor within seven days of roasting, you will lose something in the coffee on the eighth day. Once I open the green bean storage jar, I bake it as soon as possible and leave it for four days. Just use the natural circulation method so that the coffee will not be roasted too much at a time so that you can drink the best coffee.

At the same time, use large yogurt cans to store roasted coffee beans because they are not sealed so that the beans can be exhausted. It will not be affected by sunlight when placed inside because the white plastic material on the outside does not transmit light.

Many people also encourage the use of airtight jars to store roasted coffee beans to maintain the freshness of the coffee. But I want to remind you that if you are roasting at home, the storage container must allow the coffee beans to emit carbon dioxide. At the same time, you must consider the amount of roasted coffee beans. Can they be used up in a fresh state?

If the degassing is successful or not, you will experience a wonderful taste or a disappointing cup of coffee, but this is not complicated. Just pay attention to the roasting date and allow the coffee beans to emit carbon dioxide in an appropriate amount.

So remember when the coffee beans are roasted, and consider the storage space and brewing method that will also affect the degassing. The degassing time required for each coffee bean is also different, and some require a longer time to degassing. If the flavor of the coffee is not as you expected, you can try to let it out for a few more days, but be careful not to put it into expired beans.