All of our coffee bags have a valve that lets carbon dioxide out, because freshly roasted coffee needs to degas. The hole in our coffee bags is a one-way valve that lets carbon dioxide escape from the beans.
Freshly Roasted Coffee Releases Carbon Dioxide
Some carbon dioxide is released during the roasting process, but a lot remains in coffee beans after they are roasted. The beans slowly release the gas left in them, usually over the course of about two weeks. If we didn’t have a valve in our bags to let this process happen, the beans would still release carbon dioxide, and our bags would swell up with gas.
Air Harms Coffee
The valves on our bags are one-way to prevent air from getting at the roasted coffee. Both the oxygen and moisture in air can harm coffee, shortening its shelf life and detracting from its qualities, so it’s important to let carbon dioxide out without letting air in.
The release of carbon dioxide also releases a lot of coffees’ aromas, which is why squeezing air out of a puffed-up coffee bag smells so good. Next time you have a sealed bag of fresh coffee, squeeze it and see if you can identify any of the coffee’s notes in the gas that is released. You’ll be releasing carbon dioxide, but you’ll also be releasing the aromatics that make coffee so flavorful.