(a)By making milk more alkaline, it is prevented longer from turning into curd.That's why milk man shifts the ph of fresh milk to slightly alkaline by adding a very small amount of baking soda to it.

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

hope it helps.. :))