What is a one-way degassing valve?
The Pacific Bag One-Way Degassing Valve consists of a valve body, a rubber disc, and oil. The rubber disc adheres or “seals” to the valve body via a layer of the oil. This creates an oxygen-proof seal.
One-Way Degassing Valves are designed to allow pressure to be released from an air-tight package while preventing air from getting back into the package. Air, especially the oxygen (O2) portion of air, can have negative effects on the package contents and its freshness. When gas pressure inside a sealed package increases beyond the “valve opening pressure,” the seal between the rubber disc and the valve body is momentarily interrupted and gas can escape out of the package. As gas is released and the pressure inside the package drops below the “valve close pressure,” the rubber disc re-seals to the valve body and the valve is closed off to oxygen again.
What are the most common applications for the valve?
The most common application of the one-way degassing valve is for fresh roasted coffee. Fresh roasted coffees emit large amounts of gas (CO2) for several days after roasting. At the same time, coffee requires protection from air to maintain its fresh roasted taste. A coffee roaster must seal their coffee in a package that will (1) not allow air to enter the bag to spoil freshness, and (2) will allow the CO2 emitted from coffee to escape out of the bag.