How Do They Make Decaf Coffee? - Big Questions - (Ep.1)

Hi, I'm Craig. My entire body smells of coffee when I'm out in the sun

And this is Mental Floss on YouTube. Today I'm going to answer Beckinsdorf's big question

Hey Mental Floss, I have a strange question. How do they make decaf coffee when the

caffeine is in the bean? That's not a strange question. What's a strange question is why would

anyone drink decaf? But I'll answer your question. I want to begin by telling you about a 2006 study done at the University of

University of Florida. Researchers tested 10, 16 ounce decaf coffees from nine coffee shops

They found that nine of the 10 cups contained between 8.6 milligrams and 13.9 milligrams of caffeine

and 0 milligrams of purpose. Let that aside, this is still much less than a regular 8 ounce cup of coffee, which has about 85 milligrams of caffeine

The only cup that didn't contain any caffeine was instant decaf Fulgers coffee crystals

Why am I telling you this? Well, I thought you should know that decaf coffee isn't always perfectly decaffeinated

If you're trying to go caffeine-free, be aware of what you're drinking. Plus, it allows me to tell you without shocking you that the decaffeination process doesn't remove 100% of caffeine from coffee beans

Usually, 94 to 98% is removed. See, you're not shocked now because I told you that thing

So let's back up to before those decaf coffees were lying to unsuspecting consumers when they were just little caffeinated beans

Before coffee beans are ripe and are roasted, they are green. It these green coffee beans that are used in the decaffeination process Before any other step the beans are usually soaked in water or steamed because it makes it easier for caffeine to be extracted And the ideal temperature for decaffeination is 160 to 210 degrees Fahrenheit

Or blah-de-de-blah Celsius. I'm not Canadian, I don't know. There are a few different methods for decaffeinating coffee beans

One of these is called supercritical carbon dioxide decafination. Just felt like it needed to be said like that

Green coffee beans are put in a pressure vessel with air pressure at around 250 times what we're used to

Carbon dioxide in the vessel is used as a solvent to remove the caffeine

A few hours later, the carbon dioxide, now containing the caffeine, is removed from the vessel

Another way to caffeinate coffee beans is the direct solvent method. Instead of using carbon dioxide to remove caffeine, a different solvent is used like dichloromethane or ethyl acetate

Basically, Beckinsdwarf, the caffeine is in the bean, but we can use different solvents to remove the majority of that caffeine

And here's a little historical background so you can impress your friends. Decaf coffee was invented by a German man named Ludwig Roselli

in the early 1900s. He used a chemical compound, benzene, not to be confused with my last name, on green coffee beans. In those days, benzene was also used in aftershave and paint. It turns out benzene is not good for you

If you have a big question of your own that you'd like answered, leave it below in the comments. Thanks for watching Mental Floss on YouTube. See you next week. Come on by to see what's brewing

It probably won't have anything to do with coffee