What makes cream cheese go “bad”?

Expiration dates refer more to spoilage than food safety because various processing methods and stabilizing preservatives destroy dangerous pathogenic bacteria in hot-packed cream cheese. A container of cream cheese with an expired date may have a crumbly or watery texture, a bitter or sour aroma, loss of nutritional value, and even signs of undesirable, but usually harmless, mold. However, don’t forget potential environmental hazards. An opened container may be contaminated by unsafe meat and other sources of pathogenic bacteria, and flavored cream cheese may lose flavor or develop oxidized flavors.
 
Never use the same knife for processed meat and cream cheese. If a meat, such as pepperoni, is contaminated, you could transfer dangerous bacteria to your cream cheese product.
 
Source(s):
Dr. Rani Govindasamy-Lucey, senior cheese scientist at Wisconsin Center for Dairy Research, University of Wisconsin.