Milk (including its derivatives, ghee, buttermilk, cream, yogurt) is easily in the top bracket in the world of Indian food. It is the purest of edibles whose quality is sattvika (descriptive form of sattva): nutritive, agreeable, and conducive to serenity and spirituality. Sages and ascetics, who left all worldly ties behind and isolated themselves in the wilderness in search of higher metaphysical truths, subsisted on milk provided by local devotees. Milk was the one food that would not induce worldly desires or distractions in their minds. This belief in the semi-sacred quality of milk is also reflected in its consistent use as an offering to the gods. Rice pudding, for instance, is one of the commonest items offered to important household deities like Goddess Lakshmi, the goddess of wealth and prosperity. Even outside of Hinduism, milk retains its connotation of purity. The first food with which Lord Buddha broke his long fast after achieving Nirvana was milk-based.

Cow`s milk, as one would expect, is defined as second only to human milk in its wide-ranging benefits. Whatever the source, all milk was believed to have several properties in common: tasty, soothing, energizing, cool, rich, sperm-generating, reducing bile and gout and conducive to phlegm.

Milk was also an important part of the diet of ordinary people. It was not only health food par excellence; it had powerful symbolic value as an image of achievable prosperity. In agriculture-based Bengal, `milk-and-rice` became synonymous with the sustenance of a comfortable life. Vegetarians and non-vegetarians alike considered milk a precious food. Both the folktales as well as the substantial body of orally transmitted ditties (chharas) of Bengal are replete with images of milk that connote plenty and prosperity. Kings are anointed with milk and butter before their coronation. Princesses bathe in copiously flowing milk. Young girls hope to improve their complexion by washing their faces with milk. Rivers of milk, rippling waves of milk, lakes of milk, trembling layers of thickened milk, even oceans of milk recur with amazing frequency in myths, folktales, poems and songs.

It can be said that the use of milk and the general beliefs about its properties continued unchanged into the medieval period, as can be seen from literary evidence. In a tropical region, before the advent of refrigeration, the only way to preserve milk (without making it into kheer) was to repeatedly boil it, the notion of pasteurization being still far into the future. A by-product of all this boiling was the transformation of the fatty top layer into a `skin`. Each time the milk came to a boil, a new skin would form and it would be skimmed off, added to the previous layers and pressed together. These thick layers were used to make sar-based sweets. Dugdha-laklaki is layers of sar cut into squares and floating in mildly sweetened milk, sometimes flavoured with saffron. Sar fried in ghee and soaked in syrup becomes sarbhaja. Fried in ghee, layered with crushed almonds, khoa kheer and cardamom, and then soaked in sweetened milk, it becomes sarpuha.