When milk fermentation is not carried out by specific yoghurt microorganisms (Streptococcus Thermophilus e Lactobacillus Bulgaricus), but by the other microorganisms associated with the first ones, the product is commonly called "fermented milk".
The most popular types of fermented milk are:
• "Probiotics" produced from milk grafted with probiotic microorganisms which must be active and vital in the intestine.
• "Kefir" drink rich in lactic acid and probiotic bacteria. Kefir can have a small content of CO2 and alcohol both from the yeasts fermentation.
• "Ayran" drink made of yoghurt, water and salt.
• "Leben" yoghurt-by drink.
• "Rjagenk" a fermented milk treated at high temperature, with the typical dark color.