sour cream an example of a dairy product in motion; its use has been steadily spreading westwards. It is a traditional and important ingredient in Russian, E. European, German, and C. European cooking, both in savoury and in sweet dishes. In the second half of the 20th century, however, it has started to become a staple in the western parts of Europe, N. America, and elsewhere.
The attractive sour (perhaps better termed acid) taste offsets the richness of the cream which might otherwise be cloying. Sour cream is thicker than fresh cream of the same fat content. This is a result of partial coagulation brought about by the acid created during the souring process.