In an effort to preserve fresh milk, milk is fermented or cultured with a lactic acid-producing bacteria such as Lactobacillus, Lactococcus, and Leuconostoc. The fermentation process increases the shelf-life of the product, while enhancing the taste and improving the digestibility of milk. There is evidence that fermented milk products have been produced since around 10,000 BC. Different strains of bacteria produce different tastes and products.
Sour cream, made out of cream, contains from 18 to 20 percent butterfat and gets its characteristic tang from the lactic acid created by the bacteria. Commercially produced (and somewhat inferior) sour cream often contains additional thickening agents such as gelatin, rennet, guar and carrageen, as well as acids to artificially sour the product.
Crème fraîche is a soured cream containing 30–45% butterfat. It is soured with bacterial culture, but is less sour than sour cream, and has a lower viscosity and a higher fat content. It is slightly more heat stable for cooking and used commonly professional cooking for sauce making. Sour cream may be substituted for crème fraîche, and vice versa.
Traditional buttermilk was the thin, watery liquid left behind after churning butter out of cream. It was originally deemed unfit for human consumption and fed to hogs. Today, buttermilk is a thick cultured milk product inoculated with a specific bacteria to simulate traditional buttermilk. It is available in a variety of forms including skim, reduced-fat, full-fat and dried.
Yogurt is a cultured milk product produced by specific yogurt cultures, Lactobacillus bulgaricus and Streptococcus thermopiles. Some manufacturers add other probiotics, like Lactobacillus acidophilus and Bifidobacterium.
You must be logged in to post a comment.