A container assembly comprising first and second compartments. The first compartment includes a base web having a formed portion and a flat portion, a lidding material joined to the flat portion and a frangible seal positioned between the base web and the lidding material. The second compartment includes first and second barriers that are sealed to one another at peripheral edges. The first barrier has an aperture through which the formed portion of the base web extends. An upper surface of the flat portion of the base web is joined to an interior surface of the first barrier, thereby encapsulating the frangible seal within the second compartment. When the frangible seal is broken, a passageway is provided for transferring material from the first compartment into the second compartment for mixing with a second material. The second compartment may then be opened to dispense the mixture.