How does the one-way air valve of a coffee bag work?
After roasting, coffee beans need to go through a bean-raising period to release carbon dioxide to achieve the best flavor. When storing, the one-way exhaust valve is the core design to maintain freshness and master the "freshness secret" of coffee beans. The following are its key functions and principles:
1. Exhaust function: exhaust carbon dioxide to prevent oxidation
After roasting, coffee beans continue to release 2% of carbon dioxide by weight. If gas accumulates in the sealed bag, it will cause "bag bulging" and accelerate oxidation and deterioration. The one-way exhaust valve can actively exhaust inert gases (such as CO₂) in the bag to avoid pressure accumulation and keep the coffee beans fresh. The deeper the roasting, the stronger the exhaust effect and the faster the carbon dioxide release rate.
2. Isolate air: one-way seal to block oxygen intrusion
Unlike ordinary air valves, the one-way valve only allows internal gas to be discharged, and external air cannot flow back.
This design effectively isolates oxygen and prevents the aroma of coffee from volatilizing and the deterioration of ingredients.
