Instead , pasteurization wants to get a `` log reduction '' in the number of viable organisms . It wants to bring their number down so they are unlikely to cause disease ( assuming the pasteurized product is kept in the refrigerator and consumed before its expiration date ) . Instead pasteurization aims to reduce the number of viable pathogens so they are unlikely to cause disease ( assuming the pasteurized product is stored as indicated and consumed before its expiration date ) .