Sour Cream

Cream can be soured by Streptococcus lactis bacteria or some other acidifying agent. Light cream or half-and-half is fermented at 72^oF (22^oC) until the acidity from lactic acid reaches 0.5 percent. A thicker sour cream is produced if milk solids-not-fat (MSNF), vegetable gums (carrageenan), or certain enzymes are added. To be labeled sour cream, a minimum of 18 percent milk fat is required, although when sweeteners are added, the minimum milk fat content can be lowered to 14.4 percent. Lower-fat sour creams with half the fat content of standard sour cream, and sour cream substitutes, are also available.