Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Explain your answer.
Curd contains lactic acid , also the taste of curd is sour as compared to that of milk.
This indicates that curd has more acidic properties than milk.
We know that, if substance A has more acidic nature than substance B, then pH of substance A will be lesser than pH of substance B.
(The lower the pH of a solution is than 7, the more is it’s acidic concentration)
In this case, curd has a higher acidic nature than milk. Hence, the pH of curd will be less than the pH of milk. Therefore, pH of curd < 6.