Does cold water boils faster than hot water?

One of the oldest kitchen myths is the claim that cold water boils faster than hot water. To set the record straight from the outset: this is more myth than reality. Scientifically, hot water boils faster than cold water under identical conditions, due to the basic principles of thermodynamics. Now, let's dive into why this myth persists and uncover the simple science behind the boiling process.

📖Explaining the Myth

The idea that cold water might boil faster than hot water contradicts fundamental thermodynamic principles. These principles state that the amount of energy required to bring water to its boiling point depends on its initial temperature. Hot water, being closer to the boiling point, requires less energy and time to boil compared to cold water. Simple innit!

🧪What About The Mpemba Effect: A Related Phenomenon

Often, discussions around this myth bring up the Mpemba effect, where under certain conditions, hot water can freeze faster than cold water. However, it's important to note that the processes of boiling and freezing are governed by different principles, making the Mpemba effect irrelevant to our boiling water debate

🤔Why Does the Myth Persist?

Several factors contribute to the persistence of this myth:

• Evaporation: Hot water tends to evaporate faster, which can reduce its volume and make it seem like it boils faster, especially in open containers.
• Dissolved Gases: Cold water contains more dissolved gases, which are released as it heats, possibly affecting the perception of how quickly it begins to boil.
• Thermal Conductivity and Heat Sources: Variations in how heat is applied and the materials used to contain the water can influence perceptions of boiling times.

 

🔬The Science of Boiling Water

Boiling water is a process where liquid water is heated to 100°C (212°F) , transitioning to gas (steam). The speed at which water reaches its boiling point is directly related to its initial temperature and the energy applied. Hot water has less temperature to cover to reach boiling point, making it quicker to boil than cold water.

📖 Experimental Evidence

Scientific experiments designed to test the boiling times of hot and cold water under controlled conditions consistently demonstrate that hot water boils faster. These experiments take into account variables like pressure, container material, and heating method, further solidifying the understanding that the initial temperature of water is a decisive factor in boiling time.

 

🤔So, is it better to boil warm water instead of cold for cooking?

Short answer is no, although warm water reaches boiling point faster and is more energy-efficient, it's not always advisable to use hot tap water for boiling. This  is because of the potential risk of contamination, which depends on the condition and age of your plumbing system. In well-maintained, modern homes, the likelihood of contamination from hot water is quite low, but it's not zero. The main concerns are the hot water heater's tendency to corrode over time and possibly release metals into the water, along with the chance of bacteria growing in the tank. Since cold water doesn't go through the heater system, it's safer for cooking and drinking, even if it means waiting a bit longer for it to boil."

📕Conclusion: Debunking the Myth

The belief that cold water boils faster than hot water does not hold up under scientific scrutiny. While there are interesting physical phenomena, such as the Mpemba effect, they do not apply to the process of boiling water. For those looking to save time and energy in the kitchen, starting with hot water is the best practice. This exploration not only corrects a common misconception but also celebrates the role of science in clarifying the truths behind everyday myths.