I have many recipes that call for sour cream. Is this cream that has been soured or the commercial boxed sour cream that can be used on potatoes, in dips, etc.? How do you make sour cream and can that be used interchangeably with the store-bought variety?
Sour cream gets its acid taste from harmless bacteria related to the ones used to make yogurt. These bacteria are naturally present in milk, and in the old days cream went sour with some regularity. Like old-fashioned sour milk, it was still perfectly useful, and many recipes were created that took advantage of its special properties.
Pasteurization kills the souring bacteria along with everything else, so modern cream can not sour on its own. When it gets old, it rots. Dairies “culture” commercial sour cream by combining the necessary bacteria with freshly pasteurized cream under controlled conditions.
Commercial sour cream can be used in any recipe that calls for the stuff, but if the recipe is an old one, you might want to thin it with cream or milk (2 tablespoons per cup), since it is very thick. To get the best, be sure to read the label, and I don’t mean just for the date. More and more brands now contain vegetable gum and/or other thickeners, flavorings, and preservatives.
Try our recipe for the best sour cream coffee cake!