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 Bekins dwarfs 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 how do I'll answer your


I want to begin by telling you about a

2006 study done at the University of

Florida researchers tested 10 16-ounce

decaf coffees from 9 coffee shops they

found that nine of the ten cups

contained between eight point six

milligrams and thirteen point nine

milligrams of caffeine and zero

milligrams of purpose so 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 Folgers

coffee crystals why am I telling you


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 percent 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's 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-dee-blah Celsius I mean I'm not

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 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 decaffeinated

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 Bekins dwarf 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

Rose Elias in the early 1900's 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

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 a coffee