Why Coffee Bags Have a Circular Valve

Coffee lovers have probably noticed small circular valves on the front parts of most coffee bags. But many of them have no idea what these things are there for.

5-Minute Crafts would like to uncover this mystery and explain why coffee bags have air-valves.

Why there are valves on coffee bags

While most of us have tried to smell coffee through this valve, that’s not the reason why it’s there. In fact, the valve is a one-way vent that lets coffee retain its taste and freshness for a long time. It helps to prevent beans from turning stale, and it de-gasses the coffee bag, preventing it from bursting.

Thanks to the roasting process, the beans in the bag are releasing CO₂, and this gas will begin to fill up the bag. To preserve the taste and freshness of the coffee, the majority of manufacturers pack the beans right after they’re roasted, without waiting for the process of the CO₂ release to stop.

Thanks to the one-way valve, oxygen (which ruins the coffee’s taste) doesn’t enter the bag, while CO₂ leaves the bag easily.

What happens if the bag doesn’t have a valve

• A bag of coffee beans without a valve can inflate.
  With the CO₂ pressure continuously building, the bag could swell, leak, or even burst open. The de-gassing valve allows gases to escape the pouch during storage, maintaining the package’s appearance and the coffee’s freshness.
• Without the valve, the beans inside the bag lose their freshness and flavor faster.
  Even after 1 to 2 weeks, coffee becomes less tasty and aromatic.
• Coffee turns stale faster.
  Of course, manufacturers could wait until the CO₂ releasing stops, and pack coffee only after that. However, coffee beans start interacting with oxygen right after the roasting, which makes the coffee’s shelf-life much shorter.