Question

Why does a milkman always adds a little amount of baking soda (which is a alkaline) always ?

Answer 1

if some of the milk lactose was converted to lactic acid then on heating the milk with that lactic acid can cause denaturation of milk protein into cheese(paneer).
the alkaline baking soda normalises the lactic acid.

Answer 2

Answer:

Becoz baking soda is a base which reacts with acids and neutralizes it. This prevents milk from getting sour and keeping it fresh for long time...