A coffee storage container, for storing a quantity of coffee within a jar having a bottom and a side wall, and using a piston having a top and bottom, and a one-way valve. The quantity of coffee is placed in the jar bottom. The piston extends within the jar and defines a storage volume beneath the piston bottom. A stem is selectively attached to the piston top to push the piston downward to allow air to escape through the one-way valve so that the storage volume becomes substantially the coffee ...