What do expiration dates on cottage cheese refer to--quality or safety?

Provided the product is refrigerated at or below 40 F, the expiration date refers to spoilage (deteriorating taste, texture, etc.), not to unsafe contamination. An unopened container of cottage 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.
 
Dangerous bacteria are destroyed by milk pasteurization. However, once you open the carton, avoid contamination through contact with unsafe meat and other potential sources of pathogenic microorganisms.
 
Source(s):
Dr. Rani Govindasamy-Lucey, senior scientist, Wisconsin Center for Dairy Research, University of Wisconsin.