Traditional yogurt has long been popular in the U.S. Consumers love its tart flavor, creaminess and versatility. It can be incorporated into a wide range of foods.

Fat levels in traditional yogurt range from nonfat to full fat (3.5% or more). Yogurt is available plain or with added fruit and/or flavors. Other allowable ingredients can be added to help develop the desired flavor and texture.  

Manufacturing

The manufacturing process begins by combining fluid milk, additional dairy ingredients such as nonfat dry milk or whey protein powders as well as any stabilizers and/or sweeteners followed by homogenization and pasteurization. After pasteurization, the yogurt is cooled to incubation temperature (40-43C) and cultures are added to ferment lactose to create the lactic acid necessary for developing the texture and flavor of the yogurt. Fermentation then take place either in a temperature-controlled tank equipped with agitation (stirred or Swiss-style) or in the individual yogurt cups incubated in a room set to the desired fermentation termperature (set or cup set) The fermentation is complete when the yogurt reaches ~pH 4.6 (typically 4-6 hours). At this point, stirred yogurt gel is broken by agitation and cooled to stop the fermentation followed by pumping through a smoothing valve, addition of fruit and/or flavors and finally packaging. At completion of fermentation, cup set yogurt is moved from the warm room to a cooler to stop the fermentation. Note that fruit and/or flavors are added to cup set yogurt prior to fermentation.  

While vitamin fortification of milk for yogurt isn't required by law, an increasing number of U.S. manufacturers are adding vitamins D and/or A.