A polymer-based sausage casing suitable for use with uncooked meats such as chorizo is disclosed. A polymer resin is blended with a silicon-based barrier control agent, preferably a polyhedral oligomeric silsesquioxane, to increase the permeability of the sausage casing. The resultant blend can be biaxially stretch-oriented to produce a single-layered polymer-based sausage casing suitable for use with uncooked sausage meats such as chorizo, and specifically suitable for the gas and moisture permeability needed during the curing process for uncooked sausage meats. Such polymer-based casings can also be employed for cooked sausages by choosing a silicon-based barrier control agent that increases gas and moisture barrier, thereby increasing shelf-life for unpeeled sausages. A method for improving the peelability of cooked sausage casings by injecting a thin coating of a releasing agent, without the addition of a surfactant, into the sausage casing during the shirring process is also disclosed. The releasing agent is a hydroxypropyl methylcellulose solution that creates a low viscosity releasing agent that effectively improves peelability from any type of sausage casing, but preferably for use with the polymer-based sausage casing of the present invention.