Dairy products are high in fat, protein and a wide range of nutrients. That makes them appealing to humans, but it also means they're a near-perfect breeding ground for bacteria. Often this spoils them or makes them unfit for human consumption, but not always. Many of the most-loved dairy products, from cheese to yogurt, are created by combining dairy products with beneficial bacterial cultures. Several of those products are made by "culturing" cream.
How It Works
A dairy is a place that's rife with naturally occurring bacteria. Some, such as Listeria monocytogenes or Escherichia coli, can cause serious human illness. Others cause the milk and cream to change their flavor and texture, often extending their storage life. Humans have known for thousands of years that by manipulating the temperature of the milk or cream, or by deliberately adding already-cultured milk, they could encourage the growth of desirable bacteria which in turn would out-compete the undesirable, health-threatening bacteria. The number of cultured dairy products used around the world demonstrates how well the principle works.
The most familiar cultured cream product for Americans is sour cream. It has its origins in central and eastern Europe, and became common in the United States as immigrants from those regions settled in the Midwest and the large cities of the Eastern Seaboard. Sour cream averages about 20 percent fat by volume, comparable to light cereal cream. It has a rich and lightly tangy flavor, which complements a number of plain foods from baked potatoes to perogies and borscht. Its relatively low-fat content means that sour cream is poorly suited to cooking, because it tends to curdle.
Americans who travel to Europe or are food aficionados often encounter a similar cultured cream called creme fraiche. It's similar to sour cream, made by inoculating heavier cream with a similar range of beneficial bacteria. Creme fraiche is less tangy than American-style sour cream but averages 40 percent fat, meaning it can be used in casseroles and sauces without breaking down. Home cooks can make their own by adding a small amount of yogurt or buttermilk to heavy whipping cream, and letting it sit overnight.
Most American butter is manufactured from uncultured or "sweet" cream, and has a light, fresh flavor. European butter is often made from cream that's lightly cultured, giving it a cheese-like tang and rich flavor. Home cooks can make their own cultured butter by culturing cream as they would for creme fraiche, then churning it in a stand mixer or food processor the next day.
- On Food and Cooking: The Science and Lore of the Kitchen; Harold McGee
- The Cook's Thesaurus: Cultured Milk Products
- America's Test Kitchen: How to Make Cultured Butter
- Photo Credit Stockbyte/Stockbyte/Getty Images