Bulgaria is the only country where Lactobacillus bulgaricus occurs naturally in the air, giving its yogurt a distinctive tangy flavor and creamy texture.

Lactobacillus bulgaricus was first identified in 1905 by Bulgarian microbiologist Dr. Stamen Grigorov. While studying the microflora of Bulgarian yogurt at the University of Geneva, he isolated the distinctive rod-shaped bacterium responsible for the fermentation process. This discovery later caught the attention of Nobel Prize winner Ilya Mechnikov, who linked it to the exceptional longevity observed in the Bulgarian population.The bacterium is unique because it thrives in the specific geographic and climatic conditions of the Balkan Peninsula. The region's humidity, temperature, and local plant life create an environment where the bacteria naturally inhabit the air and plant surfaces. In most other parts of the world, this strain either mutates or dies out over time, forcing yogurt producers to rely on freeze-dried laboratory cultures to maintain consistency.Modern research from the Bulgarian Academy of Sciences demonstrates that the symbiotic relationship between Lactobacillus bulgaricus and Streptococcus thermophilus produces the characteristic acidity and aroma of traditional Bulgarian yogurt. This partnership works most effectively when using wild-harvested strains from the Bulgarian countryside. Today, the bacterium is a key ingredient in probiotic supplements worldwide because of its remarkable ability to survive the acidic environment of the human stomach.