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A chemist explains the chemistry behind decaf coffee

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Re: A chemist explains the chemistry behind decaf coffee

#61

Does it work the same for instant?

And if you're interested in an actually (relatively) decent instant decaf, I'd suggest trying Mount Hagen brand of instant decaf coffee. Although, just from personal anecdotal experience, I believe it could have slightly more caffeine than some other decaf coffees.

Re: A chemist explains the chemistry behind decaf coffee

#62
post #27

It is somewhat magical to me that these processes can be as selective as they are. Coffee beans must have hundreds if not thousands of organic compounds in them, and somehow something as simple as co2 (or the other solvents) picks up mainly caffeine. Somehow that is very counterintuitive to me.

Extraction and separation are a function of time, temperature, and solubility, not just polarity. It's easy to target solubility limits for certain compounds, which why using a Soxhlet extraction method could be effective for at home decaffeination.

I've always assumed that's why steam extraction for espresso doesn't extract more caffeine than drip, and why a Madras coffee decoction isn't ultra-caffeinated concentrate.

Re: A chemist explains the chemistry behind decaf coffee

#63
post #27

It is somewhat magical to me that these processes can be as selective as they are. Coffee beans must have hundreds if not thousands of organic compounds in them, and somehow something as simple as co2 (or the other solvents) picks up mainly caffeine. Somehow that is very counterintuitive to me.

I was interested and looked at the actual patent: https://patents.justia.com/patent/4348422 (there seem to be multiple patent documents, but this one adds some explanation), and he writes "I have now surprisingly discovered". https://tastydecafs.com/blogs/learn-about-decaf/co2-decaf further explains "The story of C02 decaffeination goes back to 1967. It was then when a chemist at Max Planck Institute named Kurt Zosel…

To add some clarification: decaffeination is as old as 1903 (also Germany: https://en.wikipedia.org/wiki/Decaffeination)

Re: A chemist explains the chemistry behind decaf coffee

#65
post #4

The decaf process seems expensive so you might expect the end result to cost more, but it never does. Which means either the producers are making less profit on decaf, or they are using lower quality beans. If the latter is true, which seems more likely, that might explain why decaf sometimes tastes less good, separately from the effect of the process itself on taste.

Decaf that I buy is more expensive. It is the grocery store brand and looks identical to the regular bags they sell for a similar price but on close inspection you will find the decaf contains ~9oz net weight and the regular is 12oz net weight.

Re: A chemist explains the chemistry behind decaf coffee

#66
post #49
post #47

Earlier quoted context omitted.

How quickly is quickly? I literally yesterday bought my first bag of decaf and mixed them with my regular beans. I need to sleep more, and reducing caffeine intake is the low hanging fruit. Decades of habits around buying and using normal beans are about to be replaced, and this comment is already helpful.

I think it depends how you brew it. Filter, for example, is a lot more forgiving on flavor than espresso. My decaf beans start to go bad for espresso after a few days of buying them, but for filter they will last much longer. One recommendation by coffee aficionados is to freeze your decaf beans as soon as you get them and then grind them frozen. I haven't tried that yet, I just buy in small batches so they are usual…

This is really helpful. I’m doing pour over, and I tend to use lower temperature water, so it sounds like I’ve got some leeway.

Re: A chemist explains the chemistry behind decaf coffee

#67

I'd love if all psychoactive compounds could be removed from coffee beans. The stress response and inability to sleep I get from decaf beans is pretty much comparable to that from normal beans (and distinctly different from pure caffeine or green tea)

Interesting, either the store is selling you fake decaf, or there's really a whole bunch of other chemicals, other than caffeine, that can mess with your body.

I have an unusually strong response to caffeine (a cup of coffee, strong tea, or, on a bad day, even a small glass of Coke). It doesn't really affect my heart (as far as my Apple Watch can tell), but it obliterates my sleep and makes me feel quite a bit more anxious than usual. Decaf coffee solves the problem completely — no stimulation, no anxiety, normal sleep. Coincidentally, I had a tall glass of iced decaf just two hours ago, and I'm going to bed in a few minutes.

Re: A chemist explains the chemistry behind decaf coffee

#68

I wonder why we don't use genetic modifications to get caffeine free coffee?

At least part of the reason coffee plants produce caffeine is as a defense mechanism from insects. If you genetically engineer out the caffeine, your effort to farm the plant just went up if you aren't also able to genetically engineer insect resistance.
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