What is Yogurt?
One of the oldest and most-popular fermented foods, yogurt is known around the world. Where did yogurt come from, and how is it made today?
The word yogurt comes from Turkey and refers to a tart, thick milk. Yogurt does not have one single origin, however. It can be found in nearly every culture that kept animals for milk. It was likely discovered in similar ways in each region. When fresh milk is left in a container with friendly bacteria, the milk thickens and develops a delicious sour taste. The lactic acid produced by the fermentation also acts as a preservative, helping the cultured milk stay pleasant longer.
Warmer regions favored thermophilic bacteria, while cooler areas favored mesophilic bacteria. Our Greek yogurt starter is an example of a heat loving (thermophilic) culture. Filmjolk is an example of a cooler temperature (mesophilic) culture.
Around 1900, scientists started studying and isolating the bacteria that make yogurt. Very soon after, they were able to combine selected strains that would culture reliably for commercial creameries.* These blends are called direct-set cultures. With no starter to maintain, direct-set starters made it possible for a company to consistently make the same yogurt with each batch. Thanks to their research, it is now simple to buy powdered yogurt starter such as our delicious Mild Flavor Yogurt starter and make this same yogurt at home.
In 1981, the FDA defined fresh, prepared yogurt in the US and stated that it must include Lactobacillus bulgaricus and Streptococcus thermophilus.** These strains are found in all of our direct-set starters, as well as our Bulgarian and Greek heirloom starters.
Does that mean the mesophilic starters do not make true yogurt? According to US law, these prepared cultures cannot be sold and labeled as yogurt. Traditionally, they have been known as yogurts, and most still refer to them as such. It certainly does not lessen their wonderful flavor or beneficial bacteria!
Many things have changed since people first cultured milk into a thick, tangy snack. However, yogurt is still tremendously popular and enjoyed around the world. History is likely to show that fact unchanged as long as people have access to milk!
*McGee, Harold. "Fresh Fermented Milks and Creams." On Food and Cooking: The Science and Lore of the Kitchen. Completely rev. and updated ed. New York: Scribner, 2004.
Ready to Get Started Making Yogurt?
|Cooking with Yogurt Book|