Container having a base with a convex dome and method of use

A polymeric container for holding a fluid and a gas includes a specially designed base. The base includes an annular outer ridge connected to a convex dome by a flexible annular joint. During a hot fill operation, the structure of the base resists outward deformation. The top is then sealed. During the subsequent cooling of the container, the interior volume decreases forcing the dome upward toward the top of the container thereby reducing the tendency of the sidewall to inwardly collapse. In an embodiment of the invention, the sidewall of the container has a plurality of internally protruding diagonal ridges.