History Balkan's long and affectionate relationship with yogurt dates back to the Thracians, ancient inhabitants of the Balkan Peninsula before more than 3000 years when stock-breeders placed sheep's milk in lambskin bags around their waists and fermented yogurt using their own body heat. The word 'yogurt' is derived from the words for 'thick' and 'milk' in ancient Thracian. In the early 1900s, a Bulgarian scientist called Dr. Stamen Grigorov, found an agent causing Bulgarian yogurt fermentation - a specific bacillus. Grigorov went on to pinpoint two more bacteria: a Streptobacillus and a harmful Streptoccus thermophilus which coexisted with that Lactobacillus in what appeared to be a perfect symbiosis. He also discovered that these two bacteria are not part of the micro-flora that exists in the human intestinal tract; however, they turn out to be very beneficial to it when introduced in it. Interested in Dr. Grigorov's discoveries, another scientist, the Russian Ilya Mechnikov, a Nobel Prize laureate in Physiology and Medicine, went on to discover that more people lived to the age of 100 in Bulgaria than in any of the 36 other countries he studied. He directly linked this to the country's most traditional food - yogurt. According to Metchnikoff's research, the ageing process results from the activity of putrefactive (proteolytic) microbes producing toxic substances in the large bowel. Based on these facts, Metchnikoff proposed that consumption of fermented milk would "seed" the intestine with harmless lactic-acid bacteria and decrease the intestinal pH and that this would suppress the growth of proteolytic bacteria, that he called "Bulgarian Bacillus".