laser coffee, coming soon to a café near you?
Coffee is the world’s most popular drink, with over two billion cups a day going down humans’ hatches and becoming a symbol of work, determination, and focus. At various points in history, it was so important that it’s been used as currency and shaped the history of entire nations, so much so that a popular myth states that women in the Ottoman Empire could file for divorce if their husbands failed to provide their daily quota of beans. That myth is not really true, but it doesn’t need to be given the beverage’s indisputable dominance across global history.
Lasers are one of humanity’s most ubiquitous devices, used in everything from media, robotics, communication, construction, science, medicine, weapons, and even corporate presentations. We use them to play music, aim missiles, treat cancer, and even explore what happens when matter is cooled down to absolute zero, the coldest temperature possible in physics. (After that you get into the universe of negative temperatures which is downright bonkers.) And although lasers are very much unlike coffee, our world would also be lost without them.
Now, a team of German scientists managed to combine these two very popular things to tackle the biggest problem with making cold brew coffee: the 12 to 18 hours of wait time. By using an ultra-fast laser which emits pulses lasting for just a trillionth of a second for three minutes, they were able to make coffee that doesn’t have quite as much caffeine as your standard cup of cold brew and may have been a few degrees warmer, but otherwise met all the core criteria. It was cold, the beans released their flavors, and the caffeine concentration was higher than a typical cup of hot joe.
The process works exactly like you think it should. Laser pulses generated heat, which made the beans crack and release their chemical payloads, but because the pulses were so short, neither the coffee nor the water boiled. By turning the energy on and off every trillionth of a second, the researchers managed to limit the heating to just 5 °C throughout the brewing process while increasing the efficiency with which water extracted the beans’ caffeine and flavors, which they confirmed by using a gas chromatograph and a spectrometer.
So, if you have a $30,000 laser, you too can get cold brew in three minutes instead of having to leave the appropriate contraption in the fridge overnight. While this has some pop sci writers imagining hipster baristas serving laser coffee to intrigued patrons, and I can personally see it happening in some trendy hotspots, it’s probably not going to take coffee shops by storm. Just consider that a tornado cold brewer costs about $35 and makes pretty damn tasty coffee in 15 minutes, and you can see why femtosecond laser brew probably won’t upend the industry.