Question

A milkman adds a very small amount of baking soda to fresh milk.
(a) Why does he shift the $pH$ of the fresh milk from $6$ to slightly alkaline?
(b) Why does this milk take a long time to set as curd?

Answer 1

a) When the milk is made more alkaline by adding a base to it, it is basically done to prevent it for more time to turning to curd. That’s why milkman shifts the $pH$ of fresh milk to slightly alkaline by adding a very small amount of baking soda to it as baking soda is alkaline in nature and it neutralizes the acidic nature of milk.

b) As this milk is slightly more alkaline than other, therefore, acid produced to set into curd will be neutralized by baking soda added by milkman. Hence, this milk takes a longer time to set as curd.