Blog #729 Decaf Coffee and Tea

Decaffeinating Coffee and Tea

Mostly from:  https://coffeeconfidential.org/health/decaffeination/

Wow – I’ve really be off on this coffee and tea study.  I’ve taken coffee for granted most of my life – but there are some differences.  I generally think coffee and caffeine are good (in general). I don’t want to overdo it and get jittery – and especially later in the day so I can sleep well.  [I remember years ago where I could drink coffee into the evening and it didn’t bother me – but now, I try to avoid caffeinated beverages later in the day.]

So, how do they decaffeinate coffee (first – then tea later)

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First – coffee comes from coffee beans – and coffee beans naturally have caffeine in them.  And … even when decaffeinating coffee there is still some small amount of caffeine left.

Coffee is always decaffeinated in its green (unroasted) state.

The greatest challenge is to try to separate the caffeine from the coffee beans while leaving the other chemicals at their original concentrations. This is not easy since coffee contains somewhere around 1,000 chemicals that are important to the taste and aroma of this wonderfully complex elixir.

In the indirect-solvent method the coffee beans are soaked in near boiling water for several hours, which extracts the caffeine as well as other flavor elements and oils from the beans.

The water is then separated and transferred to another tank where the beans are washed for about 10 hours with either methylene chloride or ethyl acetate. The molecules of the chemical solvent selectively bond with the molecules of caffeine and the resulting mixture is then heated to evaporate the solvent and caffeine.

Lastly, the beans are reintroduced to the liquid to reabsorb most of the coffee oils and flavor elements.

In this method of decaffeination the beans are steamed for about 30 minutes in order to open their pores. Once the coffee beans are receptive to a solvent, they are repeatedly rinsed with either methylene chloride or ethyl acetate for about 10 hours to remove the caffeine. The caffeine-laden solvent is then drained away and the beans are steamed again to remove any residual solvent.

Most of the time the solvent of choice in this method is ethyl acetate, so you’ll often see it referred to as “The Natural Decaffeination Method” or “The Ethyl Acetate Method.”

(aside – “Short-term exposure to high levels of ethyl acetate results first in irritation of the eyes, nose and throat, followed by headache, nausea, vomiting, sleepiness, and unconsciousness. High concentrations can cause CNS depression and congestion of the liver and kidneys.”) 

First, you will note that a major reason for decaf coffee costing more than regular coffee is the major steps done to the coffee beans – chemicals added, coffee bean mixture is heated for a longer period of time.  So the time, the chemicals and the intricacies of this process can be significant as compared to just regularly roasting and grinding beans.

How about decaffeinating tea?

All teas made from Camellia Sinensis contain natural levels of caffeine. Caffeine is one of many self-defense chemicals that a tea uses to defend itself in this cruel world. Pound for pound there is more caffeine in tea than coffee, but who drinks a pound of tea? So cup for cup, tea is much less. In fact, you have to drink 3 cups of tea to get the same amount of caffeine as a cup of coffee.

Different parts of the tea leaves have different levels of caffeine. The delicious but defenseless tea buds have the most, green teas have slightly less and black teas even less. Of course, you steep black tea longer than green tea, so it is a bit complicated. Still, it is correct to say that there is more caffeine in white tea than black tea. The decaffeination process almost eliminates all of the caffeine.

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And, there are also the truly, fully caffeine free teas – that really aren’t made from tea leaves at all!! 

“A confusing aspect of learning about tea is that many of the beverages which are called “tea” are actually not tea. Herbal teas are usually dried flowers, fruits or herbs steeped in boiling water. An interesting note: in Europe and some other countries, the use of the word “tea” is legally regulated to only apply to Camellia sinensis (that is – ‘real tea leaves’). Not so here in the United States…so don’t feel bad if you’ve been confused!”

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So, decaffeinated coffee still has a little caffeine; much of the decaffeinated tea is not really tea – but a mixture made of dried flowers, fruits or herbs.  

I guess, for me, I’ll stay with regular coffee, with regular tea (especially for iced tea) – but accept herbal “teas” like ‘sleepytime tea’ as a nice beverage without caffeine.  
Yup – an interesting look into two of the most common beverages in our lives.

Posted by Bruce White

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