Does Blowing On Hot Food Cool It Down

According to the University of Washington, drinking coffee or slurping on soup at a temperature higher than 110° F(43° C) will be at risk of irritating the mouth. At 160° F(71° C) you will experience burn immediately.

Despite us not knowing the exact figure stated above while consuming these hot food or drinks, most of us can guess that food or drinks that releases steam will cause injuries to our mouth if consumed.

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This is what makes some of us blow out the food first to cool it off before taking it in. However, does blowing on hot food or drinks really help in cooling them off quickly or it is just a psychological feeling altogether?

The answer will be YES!

Generally speaking, there are 3 ways to reduce the temperature of our food and drinks.

You can wait for a cooler room temperature that will change the energy of the hot fluid but this will definitely take time.
You can place ice cubes and speed up the process of cooling but your drinks will not taste the same as the ice making it more dilute.
Or you can simply blow it off by giving your cold breath to the hot fluid and ultimately cooling it much quicker than leaving it to cool off by itself.

Heat Transfer In Food

When you blow air onto the surface of the hot food, you will send air that has an almost similar temperature to your body's which is an average of 37° C(98.6° F). This cool air will be used to displace the hotter air in a process known as convection.

Since the air surrounding the food or plate is now much cooler, this will increase the rate of heat transfer.

To put it into perspective, you can imagine having one bowl of hot soup in a room in which it will take some time to cool the soup off. But if the same bowl of soup was to be placed in a room that is much cooler, the soup will cool off much quicker.

The opposite can also happen. Imagine having a cone of ice cream that is melting during the summer compared to the same cone of ice cream that melts slower when you are in a cold room.

Going back to the main question, when the food is to be left just like that, the food will still lose heat through heat transfer to the bowl by heat conduction. Blowing the food or drinks will expedite this heat transfer.

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Heat Transfer In Water

When you blow air on food that is moist, you can also cool them off by evaporation. This happens when you blow air which transfers the steam of air from the hot surface and allows more air molecules to be evaporated such as when blowing hot tea.

Since evaporative cooling is more effective, you might see liquid being cooled off quicker compared to solids. You can also speed up the cooling process by splitting or cutting the food into smaller pieces and ultimately reducing the storage of heat in the food.

Due to that, the hotter the food or drink is, the bigger the difference between the temperature of the food or drink with its surrounding. Thus this makes blowing on food or drinks speed up the cooling process.

If the food or drink is still hot, perhaps there is not much difference in the heat to make a change.

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There Are Some Food/Drinks Best Consumed When Hot

Despite all of that, it cannot be denied that there are some food or drinks best enjoyed in slightly hotter conditions.

Soup for instance is more prone to release umami when hot and makes it saltier when cold. Some people believed that soups are best consumed in temperatures ranging from 58 - 72° C(136.4° F - 161.6° F).

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