Everyone wants their coffee hot. And everyone wants to sip their coffee when it's as hot as they can stand it, before it becomes cold and unpleasant. But it's difficult to figure out when the coffee has passed the threshold from being "too hot" to "just right."
And that's why everyone ends up being scalded when they take that first, exploratory sip.
It's a problem that has baffled humanity since the 15th century, when coffee was first brewed in the Sufi Muslim monasteries of Yemen.
Thanks to a new company called Ink N Drink, we no longer need to fear burning our tongues on a hot coffee.
Ink N Drink makes marker pens whose ink changes color with the temperature. For coffee drinkers, this means that if you write someone's name on a coffee cup, the color will shift as the coffee cools, making sure that you do not burn your tongue.
When the liquid inside the cup is above 150° F, the marker will be green, and when it cools down below 150° F, it will change to a dark blue.
The idea all comes from a young entrepreneur named Jimmy Huh who is "who is hoping to 'dent the world' in some small way," according to the Ink N Drink website.
It seems like the ideal use case for these markers would be for Starbucks to buy them in bulk and hand them out to baristas. But if you don't want to wait for this to happen, you can buy yourself a marker for $3.99. And according to Gizmodo, the markers work on some ceramic mugs as well, depending on how thick the material is.
Here's how the markers work:
First you write whatever you want on a cup and pour in hot water.
Then as the hot water fills the cup, the marker will turn green.
When the temperature cools down again, the marker will turn back to blue.
And there you have it, no more tongue burning.
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