Patent ID: 7832184

Claim:
A container, comprising: a product chamber for containing a product, wherein the product chamber has a product opening that opens into the exterior, a closure member that is releasably mounted on the product opening, and an additive chamber for containing an additive, wherein the container comprises a pressure valve that connects the additive chamber and the product chamber with each other, which pressure valve has a closed position when the pressure (p 1 ) inside the product chamber is higher than the pressure (p 1 ) inside the additive chamber, and has an open position for discharging additive from the additive chamber into the product chamber when the pressure (p 1 ) inside the product chamber is lower than the pressure (p 2 ) inside the additive chamber and wherein the pressure (p 1 ) inside the product chamber is higher than the ambient pressure (p atm ) and the pressure (p 2 ) inside the additive chamber is both lower than the pressure (p 1 ) inside the product chamber and higher than the ambient pressure (p atm ), wherein the additive chamber comprises an access opening that opens to the exterior of the container, which access opening is sealed.