Yogurt

Commercial yogurt is cultured using two primary lactic acid bacteria: Lactobacillus bulgaricus and Streptococcus thermophilus. These bacteria ferment the lactose in milk, producing lactic acid which thickens the milk and gives yogurt its tangy flavor.

There is archaeological evidence of yogurt production dating back over 8,000 years in Central Asia. The process was likely discovered accidentally when milk was stored in animal stomachs, which naturally contained bacteria that caused fermentation.

Greek yogurt is strained extensively to remove the liquid whey, resulting in a much thicker consistency and higher protein content. Regular yogurt is typically only strained twice and has a thinner, more liquid texture.

Yes, traditional yogurt contains live and active cultures of Lactobacillus and Streptococcus bacteria. However, some commercial heat-treated yogurts are pasteurized after fermentation, which kills the live cultures to extend shelf life.