India, Aug. 5 -- Milk has long been central to the Indian diet. Across all social classes, fresh milk and its derivatives like curd, buttermilk, ghee, and khoa form an essential part of everyday meals. However, during the 19th and 20th centuries, this basic staple was not available to all, and what reached the market was largely unfit for safe consumption. As towns expanded and milk became increasingly commercialised, scarcity, adulteration, and contamination turned the daily supply into what colonial health officers called the "milk problem."

In the expanding towns and cities of Western India, finding milk that had been drawn, stored, and transported with any regard for basic sanitation was exceptional. The tropical heat of the subconti...