Sour cream

Sour cream (sometimes known as soured cream in British English) is a dairy product obtained by fermenting regular cream with certain kinds of lactic acid bacteria. The bacterial culture, which is introduced either deliberately or naturally, sours and thickens the cream. Its name comes from the production of lactic acid by bacterial fermentation, which is called souring.

Traditional

Traditionally, sour cream was made by letting cream that was skimmed off the top of milk ferment at a moderate temperature. It can also be prepared by the souring of pasteurized cream with acid-producing bacterial culture. The bacteria that developed during fermentation thickened the cream and made it more acidic, a natural way of preserving it.

Commercial varieties

According to US (FDA) regulations, commercially produced sour cream contains no less than 18% milk fat before bulking agents are added, and no less than 14.4% milk fat in the finished product. Additionally, it must have a total acidity of no less than 0.5%. It may also contain milk and whey solids, buttermilk, starch in an amount not exceeding one percent, salt, and rennet derived from aqueous extracts from the fourth stomach of calves, kids or lambs, in an amount consistent with good manufacturing practice. In addition, according to the Canadian food regulations, the emulsifying, gelling, stabilizing and thickening agents in sour cream are algin, carob bean gum (locust bean gum), carrageenan, gelatin, guar gum, pectin, or propylene glycol alginate or any combination thereof in an amount not exceeding 0.5 percent, monoglycerides, mono- and diglycerides, or any combination thereof, in an amount not exceeding 0.3 percent, and sodium phosphate dibasic in an amount not exceeding 0.05 percent.