You are here
Question
Is curdling of milk a physical or chemical change? Justify your statement.
Show answer
Answer
Curdling of milk is a
chemical change
.
Justification:
- When milk turns into curd, a new substance (curd / yogurt) is formed.
- Curd has very different properties from milk — different taste (sour), different texture (semi-solid), different smell.
- The change is caused by bacteria (lactobacilli) that ferment milk sugars (lactose) into lactic acid .
- This is a chemical reaction .
- The change cannot be reversed — once milk has curdled, you cannot get fresh milk back from it.
