A blow mold system including a mold body and a base portion. The mold body includes a central bore extending from a first end of the mold body to a second end of the mold body along a longitudinal axis. The first end is configured to receive a mold preform. The base portion includes a recess, and the base portion is arranged at the second end of the mold body such that the central bore and recess define a blow mold cavity in which a container may be formed from the mold preform. In embodiments, the blow mold system has at least two interchangeable base portions that allow for containers with differently-sized or differently-shaped necks to be formed.