Whether you favor mild Arabica or the more bitter Robusta beans,Coffee Bag with a one-way degassing valve is your solution to product freshness. this pouch works great for any product that needs protection from oxygen and moisture, especially foods with active ingredients such as yeast and cultures. The one-way valve releases the pressure of trapped air and gas while preventing outside air from entering the bag. Made from a combination of materials, this bag offers an aluminum interior with an excellent moisture and air barrier. Seal bag with a standard heat sealer or an adhesive tin tie (sold separately).