Question

Fresh milk has a pH of 6. When it changes into curd (yogurt), will its pH value increase or decrease? Why?

September 22, 2024

Answer

When fresh milk turns into curd (yogurt), its pH value decreases.

Explanation:

Fresh milk has a pH of around 6, which is slightly acidic.
When milk is converted into curd, lactic acid bacteria (like Lactobacillus) ferment the lactose (milk sugar) into lactic acid.
The production of lactic acid increases the acidity of the curd, causing the pH to drop below 6, usually around 4.5 to 5.5.
A lower pH means the curd becomes more acidic than fresh milk.

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