Decaf has been around for some time now, apparently first being commercialized in the early years of the 1900s. But how is it done? Has the process been improved since it was first invented? I wanted to know, and this is what I found.
Decaf was formerly made using chemicals that are now banned due to links cancer scares. At least five methods are used today to decaffeinate coffee, using organic solvents, water, or CO2.
First, all methods are applied when the beans are still green – aka not roasted – with the aim to remove at least 97% of the caffeine for American consumption, or 99.9% for EU consumption.
The trick for decaffeination companies is to remove the caffeine without messing with the rest of the bean’s important aspects.
Table of Contents
Organic solvent processes – Direct
Green beans are steamed and then rinsed with a solvent, such as methylene dichloride or ethyl acetate. Again, these are organic compounds, though that doesn’t mean too terribly much. I suspect they want people to think they’re more healthy or safe because of the title – which they may very well be.
Regardless, the solvent extracts the caffeine while leaving the other components of coffee “largely unaffected.”
The process is repeated anywhere between 8 to 12 times until the content meets the amount of caffeine removed to comply with US or EU law.
Organic solvent processes – Indirect
In this method, the green beans are soaked for several hours in hot water, then the beans are removed and either dichloromethane or ethyl acetate is used to remove the caffeine from the water.
Because of its heavy reliance on water, this can sometimes be called the “water method”.
The same batch of water is then used again, putting it through the two-step process with new batches of beans. Why?
They seems to be attempting to force the water to reach a chemical equilibrium with the beans so that the solubles that are not caffeine will stay in the beans, but the caffeine will still be pulled out. Clever!
In other words, the water is full of all the other compounds, but has no caffeine. As such, it can’t handle any more of the other things, but only being able to handle more caffeine.
How about a metaphor: You’re at a sushi buffet and can’t stand to eat another bite of sushi… but the green tea is calling you. Your belly can’t possibly hold any more solids, but since the tea doesn’t take up much room, you go for it.
It makes sense in theory, though it makes me wonder how much of the decaffeinated chemicals are still hanging around in the water after the fact.
Supercritical CO2 process
Some people get misled by the name of this one – it does still use water, but primarily uses liquid CO2 (carbon dioxide for those who are zoning out).
The beans start by being steamed, then are added to a pressurized container that has water and liquid CO2 circulated through it at 300-atmospheres of pressure, and 150°F.
The caffeine dissolves into the CO2, leaving the rest largely untouched because it doesn’t dissolve easily in CO2. Most of it, at least.
In a second container, caffeine is removed from the CO2 with additional water. The CO2 is re-used in the pressurized vessel.
It’s not clear if they consistently use the same CO2 or if they use a new batch after so many batches of coffee. It seems to follow the same thinking as the “Indirect” method above – stopping the CO2 from absorbing anything outside the caffeine from the beans.
Swiss Water process
This one seems like the healthiest of them all, and with the most potential to create a superior result – which is to say a caffeine free beverage that tastes like coffee in every other way. It was invented by a company, Swiss Water, which is where the name originates.
They first wash the beans with water, then add the beans to their Green Coffee Extract, which begins the removal of the caffeine. The extract has had all of its caffeine removed, which creates gradient pressure between the beans and the extract. This means that there is a sort of “vacuum” created between beans and the extract.
As a result, the caffeine is sucked from the beans toward the extract, most of which is then trapped within a carbon filter between the two substances.
They then remove the extract, drawing out all the remaining caffeine, and refresh the extract to be used again until the beans have had nearly all their caffeine removed.
The beauty of the process is that it genuinely seems to remove only the caffeine and not the other soluble compounds that make coffee what it is. Since it’s using a liquid with all the same compounds, it makes sense!
In my opinion, this one seems the most likely to taste like the natural, untreated stuff. But… likely the most expensive, since it’ll take time and effort to create the coffee extract, while the other chemicals and water are likely easier to manufacture.
The green beans are soaked in a hot water/coffee solution to pull the caffeine closer to the surface of the beans.
They move the beans to soak for several hours at high temperatures in coffee oils that were taken from spent coffee grounds.
The name comes from the fact that the triglycerides in the oils will pull out the caffeine – but not the flavor.
The beans are then removed and dried. The leftover oils are chemically treated to remove the caffeine, then used again for future batches.
Is decaf always worse?
It seems that, depending on the methods, they do their very best to keep everything that isn’t caffeine in the bean.
I couldn’t find any scientific studies involving double-blind taste tests, but I’d really love to see what the results are.
A lot of taste, sad to say, has to do with perception – and perception can be tainted by outside information, such as knowing one is decaf. Try it yourself some time by having your friend surprise you, then see how often you get it correct
Where can I find decaf beans?
At nearly every store that sells caffeine, I’m fairly sure. The main question may be the method they use to extract the caffeine, as I believe different methods produce different results. A specialty coffee shop should know, but if not, the bag might have the information listed.
Though, It does seem to depend entirely on the brand. I may go through and make a list of the most popular brands and their decaffeinated method if enough people ask.
It isn’t the coffee company themselves that decaffeinate the products either. They outsource to third-party caffeine companies which may or may not concentrate and sell the extracted caffeine as pills or to energy drink companies.
I haven’t looked into that, but it definitely makes business sense to me.
Is decaffeinated coffee bad for you?
As far as I can tell, it doesn’t seem to have any real negative effects.
If anything, it’s probably healthier for you than normal coffee, as there’s no spiking of energy levels, you will sleep better at night, and you can’t withdraw from something you didn’t take.
In addition, it has all the same health benefits of coffee, though maybe slightly reduced depending on the method used.
Some places said that decaf can have 5/6ths of the amount of some antioxidants and polyphenols that normal coffee has. That doesn’t seem like a big trade-off to me if caffeine makes you feel uncomfortable or you have a bum ticker.
Standard coffee can also cause acid reflux, while it seems that decaf’s effect isn’t nearly as strong. Interesting to note, as most people blame the acidity of coffee.
In short, it seems that you’re getting a little less of the positive effects of caffeinated coffee, but much less of the negative effects, so take your pick.
I don’t know about you, but that was more complicated than I ever guessed it would be. After writing this article, I have come to think that it’s possible that decaf coffee could taste just as good as the regular stuff – and might be the better choice. It may all simply boil down to the method that the company chooses.