How to Spell Unpasteurised in English?

What means unpasteurized?

: not subjected to pasteurization : not pasteurized unpasteurized milk.

Is it pasteurized or pasteurized?

Pasteurization or pasteurisation is a process in which packaged and non-packaged foods (such as milk and fruit juice) are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life.