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) Milk is made slightly alkaline so that it may not get sour easily, due to the formation of lactic acid in it.
(b) The alkaline milk takes a longer time to set into curd because the lactic acid formed has to first neutralise the alkali present in it.