Why A Watched Pot Never Boils – The Scientific Explanation

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Have you ever heard the saying “A watched pot never boils”? It might sound like an old wives’ tale, but there is actually a scientific explanation for it. In this blog post, we will delve into the reasons why a pot of water may seem to take forever to boil when you are keeping a close eye on it. Get ready to discover some fascinating insights into the laws of thermodynamics and the workings of the human brain.

Why A Watched Pot Never Boils – The Scientific Explanation


The phrase “a watched pot never boils” is a common idiom that suggests that things we anxiously wait for seem to take longer to happen. It’s often used to convey the frustration of waiting for something to happen while staring at it, only for it to take seemingly forever. Have you ever wondered why this is the case? Why does a watched pot never boil? In this article, we’ll explore the scientific explanation behind this phrase.

The Science behind “A Watched Pot Never Boils”

When we cook with a pot of water, we typically turn up the heat and wait for the water to boil. During this time, the water heats up and reaches a boiling point of 100°C/212°F. When the water temperature reached 100°C/212°F, the water molecules at the bottom of the pot starts vibrating, turning into steam and rising to the surface, leading to bubbles formation.

However, when we stand and watch the pot, waiting for the water to boil, our anticipation may make the process seem much longer than it really is. This is because, from a psychological standpoint, when we eagerly wait for something, the perception of time slows down. Hence, it seems like the water is taking longer to boil when we wait for it to happen.

Factors Influencing Boiling Time

Several factors can affect the boiling time of water in a pot, including:

  • The amount of water in the pot: A large amount of water will take longer to boil than a small quantity.

  • The intensity of the heat source: The hotter the stove, the quicker the water will boil.

  • Altitude: Water boils at a lower temperature at high altitudes, meaning it will take longer to heat to boiling point and longer to boil for cooking.

  • The size and shape of the pot: A wide and shallow pot will allow water to boil quicker than a tall and narrow pot because of heat spread in the water


The phrase “a watched pot never boils” is simply an illusion caused by our perception rather than any scientific reality. Water always boils at 100°C/212°F, given the right amount of heat, and takes the same length of time to do so regardless of whether we’re watching it or not. The scientific explanation behind why a watched pot never boils, is that our brain is wired to perceive the time as moving slowly when we focus and eagerly wait for something to happen.


  1. Does adding salt to water make it boil faster??
  • Adding salt to water does not affect the boiling point or the time it takes for water to boil.
  1. Does covering the pot make a difference?
  • Yes, covering the pot will allow the water to boil faster by trapping in the heat and allowing the steam to cook the food.
  1. Does the boiling time differ when boiling different liquids?
  • Other liquids differ in boiling points so their boiling time varies depending on their boiling point.
  1. Does the type of pot affect boiling time?
  • Yes, the type of pot can affect boiling time. A wider pot will allow water to boil quicker and evenly than a narrow or deep pot.
  1. Is the boiling point of water affected by altitude?
  • Yes, the boiling point of water is affected by altitude. At higher elevations, the air pressure is lower while boiling point is lower to what it is at sea level, therefore, making it take longer to boil.