Question
Sun July 01, 2012 By:

Fresh milk has a pH of 6. How do you think pH will change as it turns into curd?Explain

Expert Reply
Sun July 01, 2012
The pH 6 of milk is due to the casein (milk protein) which is a phosphoprotein and therefore milk is slightly acidic.

During formation of curd, the lactobacillus keeps growing and it breaks down the lactose (the natural sugar in milk) into lactic acid which acidifies the milk even further. 

So, the pH of the milk will drop (decrease) (as the more acidic the substance the lower the pH) as it gets converted into curd.
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