Milk no doubt contains all the constituents needed for the body. But the difficulty is that it does not suit some constitutions. That is why it is sometimes said that instead of taking milk directly, it may be better to convert the net quantity of the milk needed for the body into curds and then consume it in that form. All the contents of the milk will naturally enter into the curds. But it does not mean thereby that the qualities and properties of the latter remain the same. The very act of such a conversion results in many changes in the properties. Milk and curds do differ a lot here.
Milk is a longevity promoting rasayana or an elixir; this property simply does not exist in curds. Consumption of milk is advised daily and constantly, while this is not so with the curds. Ancient Acharayas like Sushruta advise in fact not to eat curds in the night meals. Even now the use of curds and butter milk as a routine ingredient is a characteristic of the South Indian meals alone; infact, a South Indian would not feel his meal complete unless he takes curds rice at the end. But this is not so with the North Indian meals; curds is mostly optional there.
Milk is converted into curds by adding a sour substance in it. The quantity used of the later and the duration of the curds making determine the sourness of the finished product. If the temperature of the surroundings is more as in summer, the process takes place quicker. During these days the quantity of the sour substance needed is smaller and the process is also quicker. Both are in reverse order during cold weather.
In terms of taste one can distinguish three types of curds. That which is made by using as little of the sour substance needed and prepared in the shortest time is dense and sweet. Greater addition of the substance and longer duration renders it sour. A 24 hours of duration would make the curds most sour.
All types of curds are sour to lesser or greater degree. They are also astringent but to a slight degree only. The sour taste is what increases in general the relish of food substances. That is why curd constitutes an important ingredient in preparing tasty dishes like koshimbtr, rayta or tatr patchadi cuddy and so on. Taken in small quantities this promotes hunger greatly.
Curd happens to be hot in quality, unctuous or oily In nature, strengthening and also nourishing. But Its use in excess is harmful; this will lead to an augmentation of phlegmatic tendencies. Taking curds again and again is a sure measure to increase fat and obesity. An obese person is best advised not to use curds at all. Excess of using curds also leads to asthmatic bouts, cough. amavata (or torpor due to defective digestion) and such other complaints. For persons using sour curds in excess, a vitiation of blood will ensue and this is followed by an incidence of various types of skin affliction. His very skin will become blackish. A patient of skin diseases should totally avoid curds. In the disease of leprosy and eczema particularly, curd is definitely deleterious.
Sour curd promotes biliousness or pitta dosha. Thus patients of bilious eruptions on the skin, tendency of bleeding in many places and the like should also avoid curd altogether. This is to be avoided in the following afflictions also. Loss of hunger, oedemas and swellings, giddiness and high blood pressure. Buffaloe’s milk which is not so sour as that of either goat’s milk or cow’s milk is always more salutary.
As sour curd happens to be deleterious, there is a practice in some places to use curd that is not fully ready; but. this is more harmful and therefore better avoided.
In fine it is not incorrect to say that while milk is generally wholesome and salutary, curd is generally unwholesome and non-salutary. Still however, in cases of old chronic cold, advanced dysentery, difficulties in passing urine, tastelessness and the like curd happnes to be beneficial. Adding black pepper with curds will reduce the deleterious effect of the latter.