Sour cream should not be frozen. Freezing causes the sour cream to separate, and it will not blend back together acceptably.
This document was extracted from: (1)"So Easy to Preserve", 5th ed. 2006. Bulletin 989, Cooperative Extension Service, The University of Georgia, Athens. Revised by Elizabeth L. Andress. Ph.D. and Judy A. Harrison, Ph.D., Extension Foods Specialists. (2) “The Food Keeper.” Food Marketing Institute and Cornell University. March 1996.