It is unpasteurized and unfiltered, and the wort reaches the boiling point but never boils.
1881, with -ize, after Louis Pasteur (1822-1895), French chemist and bacteriologist, who invented the process of heating food, milk, wine, etc., to kill most of the micro-organisms in it; distinguished from sterilization, which involves killing all of them. The surname is literally "Pastor." Related: Pasteurized; pasteurizing.
pasteurize pas·teur·ize (pās'chə-rīz', pās'tə-)
v. pas·teur·ized, pas·teur·iz·ing, pas·teur·iz·es
To treat by pasteurization.