Pre-form assembly to make a container for beverages and container for beverages

Pre-form assembly to make a container for beverages comprising an external pre-form and an internal pre-form, each configured to form respectively an external drum and an internal bag of said container, said internal pre-form being associable internally with said external pre-form so as to define with said external pre-form a hollow space, wherein said internal and external pre-forms comprise respective coupling members in correspondence with respective neck portions suitable to reciprocally position said external pre-form and said internal pre-form along a longitudinal axis, characterized in that at least one of either said external pre-form or said internal pre-form comprises at least one spacer element protruding toward the inside of the hollow space, extending circumferentially or helically and defining at least one channel for the passage of a fluid.