What is
Lassi is a popular, traditional, yogurt-based drink from the Indian Subcontinent and is popular in India. Lassi is a blend of yogurt, water, spices and sometimes, fruit
  
Soured milk is a food product, distinguished from spoiled milk, and is a general term for milk that has acquired a tart taste, either through the addition of an acid, such as lemon juice or vinegar, or through bacterial fermentation.