Sour Cream

A Definition

Sour cream is cultured or acidified light cream. Cultured sour cream, which is the more common type, is soured and thickened by adding lactic acid bacteria to pasteurized cream with at least 18 percent milkfat. Acidified sour cream is soured and thickened by the direct addition of an acid, such as vinegar, instead of a fermentation process.

The Facts

Early versions of sour cream were created when fresh milk was left to sit at room temperature and the cream rose to the surface. Naturally occurring bacteria soured it. Sour cream is prominent in central and eastern Europe, where it has traditionally been added to soups and stews (goulash, borscht). Immigrants brought it to America where it has become a base for dips and salad dressings, a topping for baked potatoes and for use in baking.

The Process

Cultured sour cream is made by adding a culture of Streptococcus lactis to pasteurized light cream and incubating at 72˚F until the desired flavor and thickness is reached. The lactic acid produced by the culture coagulates the protein, thickening the cream and adding the characteristically sour flavor. Nonfat milk solids and stabilizers may also be added. The milkfat content of sour cream products depends on the milkfat content of the milk or cream from which they are made.

Storage and Handling

• Store sour cream in its closed container in the refrigerator, which is typically set at 38˚F-40˚F.
• If separation occurs, gently stir the liquid back into the sour cream.
• If any mold forms on the cream’s surface, discard it immediately.

Nutrition

As a food ingredient or condiment, sour cream can be incorporated into a well-balanced diet.

* Nutrient Data Laboratory Home Page, http://www.nal.usda.gov/fnic/foodcomp

Cooking with Sour Cream

Sour cream has many uses in baking, cooking and as a condiment. The richness and acidic nature of sour cream creates a moist and tender texture in baked goods. Sour cream is the base for many dips and dressings, is a popular topping for baked potatoes and produces tangy, smooth soups and sauces. The relatively low milkfat in sour cream (18-20 percent) makes it susceptible to curdling at high cooking temperatures. To prevent curdling when using sour cream in hot dishes, add it as late as possible during preparation, heat gradually and stir gently. Sour cream can be used to enrich a dish after cooking and just before serving. Care should be taken when making substitutions for regular sour cream. Reduced- fat sour cream can be substituted in a variety of dishes, including some baked goods and hot dishes, but nonfat sour cream is best substituted in cold dishes.

Glossary of Terms

Regular Sour Cream is made from light cream and contains no less than 18 percent milkfat.

Reduced-Fat Sour Cream is made from half-and-half and must contain at least 25 percent less milkfat than regular sour cream, though many on the market contain 40 percent less.

Nonfat Sour Cream contains no more than 0.5 gram milkfat per serving and includes stabilizers as thickening agents.