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 drinks decaf,

but I'll answer your question.

I want to begin by telling you about a 2006 study done at the University of Florida

researchers tested ten 16 ounce decaf coffees from 9 coffee shops

they found that nine of the 10 cups contain between 8.6 milligrams and 13.9 milligrams of caffeine

and 0 milligrams of purpose.

Put that aside this is still much less than a regular eight-ounce cup of coffee which has about eighty five milligrams of caffeine.

The only cup that didn't contain any caffeine was Instant Decaf folders 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 caffein free, be aware what you're drinking plus it allows me to tell you without shocking you

that decaffeination process doesn't remove a hundred percent of caffeine from coffee beans usually 94 to 98 percent is removed.

See, you are not shock now because I told you that.

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

Before coffee beans are right and are roasted they are green

It's these green coffee beans that are used in a decaffeination process

before any other step the beans are usually soak in water or steam

because it makes it easier for caffeine to be extracted

and the ideal temperature for decaffeination is a 162 to 210 degrees Fahrenheit

or blah de blah Celsius. I'm....not a Canadian I don't know.

There are a few different methods for decaffeinated coffee beans one of these is called supercritical carbon dioxide decaffeination

just felt like it needed to be said like that green coffee beans are put in a

Green coffee beans are put in a pressure vessel with air pressure at around two hundred and fifty 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 decaffeinated coffee beans is the direct solvent method

Instead of using carbon dioxide to remove caffeine a different solvent is used like that chloro methane or ethyl acetate

basically back in store 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 and Ludwig Roselli in the early nineteen hundred's

He used the chemical compound benzene, not to be confused with my last name

I'm green coffee beans. in those days benzene was also used in after shave and pain it turns out benzene is not good for you

if you have a big question on 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 bruin you probably won't have anything but coffee.