Patent ID: 8726616

Claim:
A method of compensating for vacuum pressure changes within a container, the container including a neck portion, a body portion, and a base portion, the base portion forming a bearing surface for the container and having a bottom end thereof with a hinge and a base wall, the base wall being adapted to be repositioned about the hinge from a first position extending outwardly to a second position extending inwardly, the method comprising: hot filling the container with a product; sealing the container with a closure; cooling the hot filled container; and repositioning the base wall about the hinge from the first position to the second position, thereby reducing the negative internal pressure of the container, wherein prior to said repositioning, the container is adapted to stand upright on a flat surface; and wherein the base wall includes a plurality of creases to facilitate repositioning thereof, the creases being adapted to flex during repositioning of the base wall.