Why does coffee exhaust? What does this mean for baristas and roasters?

This article is shared on the website Perfect Daily Grind

Why Does Does Coffee Degas&What Does It Mean For Brewers&Roasters?

Author: Behmor

The fresher the coffee, the better, right? Yes... but not entirely.

No one wants to drink aged coffee, but brewing coffee immediately after roasting can also lead to a disappointing taste due to the exhaust of coffee.

Whether you are a roaster or a barista, you need to understand this. Therefore, let's explore what coffee exhaust is, how it affects your brewing process, and what measures should be taken to address it.

What is coffee exhaust?

Exhaust refers to the gas released from roasted coffee. When roasting coffee, gas (including a large amount of carbon dioxide) is formed inside the coffee beans.

In the first few days after roasting, a large amount of these gases will be released. When you brew coffee, the escaping gas can cause small bubbles. These air pockets can disrupt the contact between coffee grounds and water, resulting in uneven extraction of flavor and aroma compounds from dry coffee.

In other words, if you brew freshly roasted coffee, it may have a negative impact on the flavor and flavor of the coffee.

Therefore, it is best to wait for a few days after roasting before brewing coffee. The time period and the chemical releases that occur during this time are called exhaust.

Why is carbon dioxide always present in coffee?

During the roasting process, coffee beans undergo many different chemical reactions. Complex carbohydrates are broken down into smaller molecules, causing beans to turn brown and produce large amounts of water vapor and carbon dioxide.

When you hear or see a burst, it is actually the accumulation of gas, causing enough pressure to break the cell wall of the beans. However, the production of gas continues throughout the entire roasting process.

Ensei Neto is the founder of The Coffee Traveler. He told me, "The most important chemical reaction is at the end of roasting, because that time is when the saccharification reaction occurs. When energy is released, gas is produced

Coffee exhaust: 'At the right time'

However, carbon dioxide in coffee beans is not a bad thing: it plays an important role in the quality of coffee. It is an indicator of freshness, playing an important role in shelf life and packaging, affecting the extraction process, participating in the formation of fats, and potentially affecting sensory data in cup testing, "said a 2018 report in Agricultural and Food Chemistry.