Question

Why do mustard seeds crackle in hot oil?

Answer 1

Hint : Mustard seeds contain water. When mustard seeds are dropped into hot oil and if the temperature of the hot oil is more than ${100^ \circ }C$, it causes the water in the seeds to evaporate. This increases the pressure inside the seeds.

Complete Step By Step Answer:
The reason behind cracking of mustard seeds when they are placed in hot oil is because of their moisture content. When mustard seeds are placed in hot oil, the water in the seeds try to escape which makes them pop open. As a result of this, a crackling sound is heard. When we make popcorn we hear a crackling sound. This is also because of the same reason. If the heat is high the mustard seeds will pop instantly and we may not even notice it. In case, if the heat is not too high, they will saute and they will be burned eventually. If the seeds are put in a cold pan with oil and covered and are given high heat, then they will start popping eventually.

Note :
To make mustard seeds without burning, heat the oil and remove the pan from heat when it becomes hot or you can also lower the heat and then add mustard seeds. It is necessary to cook mustard seeds or pop the mustard seeds for more than five to ten seconds, otherwise they will burn.