From The Food Encyclopedia by Jacques Rolland and Carol Sherman
A thick cream that has been artificially soured. Old World sour cream was nothing more than heavy, sweet cream allowed to sour in the warmth of the back of an old coal stove; it was rather thin and varied from mildly tart to quite acidic. Modern dairy technology has created a cultured product in which special bacteria are added to the cream through a series of exposure to extreme heat and pressure, achieving a thick texture and consistent taste. Sour cream can be brought to a boil without curdling. See also crème fraîche.
