When it comes to coffee, it is no surprise that many people love it. Whether hot or cold, this drink, known for fueling energy and shaking off sleepiness, is a popular choice for many.
For some, their morning is not complete without a cup of coffee to kickstart the day. Not only that, some people are willing to spend tens of ringgit, or even more, every day for their favorite cup.
In this fast-paced world, buying coffee from a café is often seen as more practical and time-saving.
But have you ever noticed that every cup of hot coffee comes with many special features, each designed with a purpose?
For example, if you pay attention to the cup lid, besides the opening we use to drink from, there is a tiny hole that serves a different function.
At first glance, its needle-sized appearance may seem like a mistake or just decoration. However, if observed closely, it actually serves several important purposes.
Small Hole but Mighty Role
This tiny hole is not just an air vent. Hot coffee inside the cup produces a lot of steam because of its high temperature.
This small hole allows the steam to escape, preventing it from building up inside the cup without cooling the drink too quickly.
But this tiny vent has another, perhaps even more important function.
Unnoticed by many, when your lips are placed near the drinking hole of a closed lid, a small air seal forms. This creates a light vacuum inside the cup when the drink is sipped.
This little hole is also known as the pressure equalization port. Not just letting steam escape, it also allows air to flow in continuously, maintaining pressure balance inside the cup.
Smart Ventilation from Your Coffee Cup
The steadier the airflow through this vent, the smoother the coffee flows out of the drinking hole. If the hole is too small or clogged with foam, the coffee may come out unevenly, causing interrupted sips.
When airflow is blocked, a vacuum can form, and the coffee will not flow properly.
In short, this process is very similar to an experiment many of us did in school, where we tried to figure out the fastest way to empty a water bottle.
Turning the bottle upside down alone causes the water to trickle out unevenly and spill. But if the bottle is first swirled to create a vortex, air and water can move smoothly together.
So in reality, every special feature on a coffee cup is not accidental; they all serve a purpose.
Source: Mental Floss