A chemist explains the chemistry behind decaf coffee | Hacker News Reader

A chemist explains the chemistry behind decaf coffee

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265 pointsBerislavLopac172 comments

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.

I suspect that when you buy decaf beans from a roaster they don't aren't the ones decaffeinating the coffee beans. I think roasters have a lot less choice when buying decaffeinated beans so I bet your theory is correct.

There are two main decaf plants, one in Vancouver and one in Mexico.

The Mexican one is supposedly superior in taste, but the majority is processed through Vancouver with the Swiss Water plant. https://www.swisswater.com/blogs/sw/swiss-waters-new-decaffe...

Is this for North America or worldwide?

Definitely not worldwide, Colombia has a plant doing EA decaf

I've noticed many roasters have only one decaf option. But there are exceptions. Equator Coffees has many blends available in both regular and decaf, with the decaf costing slightly more (e.g. $15.30 vs. $15.75 for a subscribe-and-save 12 oz bag). They advertise "decaffeinated using the mountain water process of caffeine extraction", which I believe is the same as the article's Swiss water process. Not sure if they have their own equipment or if they assemble their blends, send them off, get them back and roast them.

The decaf I buy states they have close ties with the farmers. The company they use for decaffeination seems to be a service-oriented company. You send them the raw coffee, they decaffeinate it, and then send it back with recommendations for roasting.

So, the "roaster" (if they don't use a separate company for that) does have the ability to select the exact same beans between their decaf and regular coffee products. Whether they sort the beans they get from the farmers and choose which go to be decaffeinated according to some criteria, is a separate thing.

Maybe the extracted caffeine has some market value that can make up for some of the cost of extracting it.

Dry Arabica beans are about 1.5% caffeine by weight. Synthetic caffeine costs maybe $40 per kilogram, wholesale. A kilogram of beans could have perhaps $0.60 worth of caffeine extracted from it, unless there's a price premium for "all natural" caffeine extracted from beans.

I’ve seen it marketed as “organic caffeine” in some beverages. Organic coffee was the base.

Bit of an eye roll from me, but hey whatever.

The German inventor of a decaf process sold the extracted coffein separately in pills, which might have given him a second income: https://en.wikipedia.org/wiki/Ludwig_Roselius

I guess nowadays most of the extracted caffeine ends up in energy drinks like Red Bull.

This is like what happens with milk fat. I was surprised to see whole milk cost more, and I found out that it's because the fat skimmed off is used for other products.

Same with yogurt. Whey protein isolate goes for $11/lb, which is ridiculous pricing as a side note.

Yoghurt doesn't generally produce whey. Cheese does. Whey protein used to be the cheapest form of protein by a long way because it was just a byproduct that doesn't taste good and most people have no need for. But we are now in an age where regular people buy stuff with the word "protein" slapped on it, for some reason.

Most people in this world don't eat enough protein (cca 65g daily for average human IIRC) and way too many carbs, hence a lot of civilization diseases. Or ratio protein : carbs (ideally complex) : fats (ideally unsaturated) is bad long term.

But its true that not healthy food that has some additional protein mixed in ain't magically healthy.

> don't eat enough protein (cca 65g daily for average human IIRC) and way too many carbs, hence a lot of civilization diseases

We as a specie haven't eaten as many protein as today since the invention of agriculture millennia ago, so idk what you mean by “civilization diseases” but if you mean diabetes and such, then it's clearly wrong.

We're currently eating too much and too much sugar though.

There's apparently scientific studies that show how animals as well as humans tend to continue eating until they've satisfied a mostly fixed daily need for protein, mostly regardless of _what kind_ of food they're eating.

Now if people choose a diet low in protein/calories ratio, they'll have a tendency to ingest more calories than people who eat protein rich diets. Try eating eating 300 g of cheese/meat/tofu in one meal, it'll be difficult. Eating 300 g of chips/fries is something many people can absolutely do, if the chips aren't too salty.

One significant difference between our modern western lives and the lives of people tens to hundreds of years ago is IMO that people back then quite automatically used up all the carb calories of their comparably protein diluted diet because life required much more physical activity and came with less home heating than today. Today, most people will just not expend much of the caloric energy of carb rich diets and thus develop metabolic diseases and such.

A carb rich diet is usually fine as long as you expend the energy via physical activity.

> Try eating eating 300 g of cheese/meat/tofu in one meal, it'll be difficult. Eating 300 g of chips/fries is something many people can absolutely do

I don't know where you get the idea that eating 300g of meat is difficult …

> A carb rich diet is usually fine as long as you expend the energy via physical activity.

Any balanced diet is fine if you ingest no more energy than you spend, which is exactly what I said: people today are eating too much.

> .. don't know where you get the idea that eating 300g of meat is difficult.

You're right, 300 g of meat isn't much of a challenge. The more appropriate comparison would be between 300 g of chips and an equal amount of calories in some protein rich food like meat. That should be much more challenging.

> .. people today are eating too much.

Yeah, the important question is: why are they eating too much?

I assume that a lot of it is unintentional. Overeating mostly happens because people aren't aware of a few simple mechanisms or are misunderstanding them, not because the world is hard. Mechanisms which they could quite easily use to overeat less or avoid it altogether, instead of falling prey to them.

Just telling people that they're eating to much doesn't help in any way. People need to know why and how they can quite easily change it.

The reason is because whey protein has some huge advantages for modern consumers. It stores for long periods, can conveniently be added to smoothies, and has an incredibly high protein content. When people are for example weightlifting this is a massive boon for reaching macro targets.

People into bodybuilding have been using whey protein for decades. There's not that many extra people into bodybuilding now to account for the extra demand.

There are orders of magnitude more people exercising at gyms with the specific goal of achieving some kind of desired body type, even if they aren't bodybuilders per se.

Theres definitely a much larger population who cares about 'macros' now vs just those specifically in the bodybuilding space. A very high percentage of people that workout regularly in any capacity supplement their protein. Whey protein is generally the most economical way of doing that.

Wow I sure wonder why people might want to supplement their intake of vital macro nutrients in a world where they do not get enough from a typical diet.

Not true in my experience - at least when I buy decaf beans online they are normally more expensive, which I put down to them being niche in comparison.

I don't know if this makes a difference, but my understanding is that most additive/non-natural (for lack of better terms) caffeine comes from caffeine extracted to make decaf.

>but it never does

Depends on a producer, I guess. Where I'm from, same amount of decaffeinated coffee by the same producer is around 42% more expensive.

The same decaf coffee is more expensive. The producers decaffeinate their lesser coffees. But you've hit on why the "sugar-cane method" i.e. the solvent based approach produces better coffee. It's possible for it to be done at origin and so the actual coffee producers can choose what coffee to decaffeinate and can absorb some of the additional costs in the "processing" stage while using higher quality coffee in the process.

CO2 can be reused so it's not that expensive, and the caffeine that gets extracted is sold separately, so it's possible decaffeinated coffee could have more profit that caffeinated.

After all, we don't really make synthetic caffeine, we extract it from tea and coffee and add it to a lot of things.

Synthetic caffeine has been commercially used in beverages and medicine for over 100 years. I believe that most caffeine consumed today is actually synthetic, but it's hard to find a good citation for its prevalence. Most of the web pages mentioning synthetic and natural caffeine are spam for "market research" reports or natural health woo.

You can see section "2.1. Production and use" for some relevant information about synthetic and natural caffeine production, as well as dated 20th century statistics about synthetic production:

"Coffee, Tea, Mate, Methylxanthines and Methylglyoxal"

https://www.ncbi.nlm.nih.gov/books/NBK507027/

My statement of synthetic not being super prevalent comes from a memory of a really old how it's made episode, so it could be wrong or out of date

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.

Boutique-roasted decaf coffee beans often are more expensive. But the logic also doesn't hold: it assumes coffee is being sold at or near the cost of its material inputs, and that's certainly not true. If you have a reasonable built-in margin for your coffee --- and boutique roasters certainly do --- it can be normal and rational to price irrespective of your cost basis. Customers are brand-loyal (especially if they have to go out of their way to buy your stuff). You want to get them in every packaging they're interested in. All sorts of products are "loss leaders", for that reason, and here we're not even talking about that; we're just talking about something slightly less profitable.

Finally, just a note that the "lower-quality bean" thing is itself sort of hollow, in that: you're probably not buying the absolute best quality means no matter what coffee you buy, even if you're driving to a coffee roaster to get them. Unless you're an extreme coffee weirdo, there is, I'd confidently bet, a higher-quality bean available to you that you're sacrificing because of cost and convenience. Certainly, if you're buying beans of any sort at a supermarket, the "best bean" thing is inoperative.

GP observed that either the profit margin or the input cost is absorbing the difference, so I think the logic holds well and you are in agreement :)

Not so much? Like I said: decaf beans often are more expensive, and they believe margin hits for decaf are unlikely, which is probably not at all true unless you're talking about Starbucks.

The premise may not hold - you're right - but the logic seems to.

The price difference between cheap supermarket coffee and high-end local roaster is large enough (up to 10x) that the potential additional cost for decaffeination doesn't seem that big of a deal if you're looking for coffee at the higher end of the quality scale.

Yeah, that's a much better and more concise way of saying what I did.

You both described the same thing, but fabian2k better.

I protest! Thou hast mistaken mine claim!

I thought the means should be beans

The ends justify the beans.

they either resell the caffeine for a profit themselves,

or often the coffee producer send the beans to be decaffeinated, which is done for free. the company doing that process keeps the caffeine and resell it to pharma companies

Decaf is bad business becuase processed beans are loosing taste more rapidly. You should drink it freshly roasted, buy more often but smaller packs and if this is not the case decaf simply tastes less good.

So as a producer you have more expensive process and less consumer satisfaction...

> So as a producer you have more expensive process and less consumer satisfaction...

This is illogical. People buy decaf for several reason, that don't include it's taste. Either they're allergic to coffein, they get nervous from it, they get elevated heart rates from it, or want to enjoy a coffee in the evening. All of of these reasons are fulfilled, therefore satisfactory.

Personal note: I don't taste a difference in caf and decaf and ALWAYS prefer decaf.

They use higher-caffeine beans for decaf coffee - Robusta instead of Arabica. Robusta beans aren't considered as good so they're cheaper, and they sell the caffeine they extract to e.g. soda companies.

Just not true. Cheap coffee is already robusta anyways, and arabica is used in good quality decaf coffee. Even still, arabica is consistently used as a marketing bullet for coffee… even if there’s plenty of really really bad arabica coffee out there.

There is nothing saying that a product needs to pay for all the processes inherent in making that particular product.

There is value in having flat pricing across all your products. Especially if some of them aren't as popular, yet might driving purchasing decisions.

Consider cafes that need to stock decaf, but want to buy from a single supplier. If you don't have decaf you're not going to see their custom, despite their order largely being non-decaf.

So they'll want to supply decaf, but in order to encourage the sale of it (so they can reach a better economy of scale) keep the price the same as the equivalent non-decaf.

> decaf process seems expensive so you might expect the end result to cost more, but it never does

Where? Decaf coffee does cost more...

View it as a separation process wherein both products can be sold; the caffeine extract is also profitable.

A good video explanation from James Hoffman: https://youtu.be/yYTSdlOdkn0

And a quick follow up: https://youtu.be/IszQ2JR3Olc

I can’t recommend James Hoffmann’s channel enough - he’s such a passionate coffee guy who’s just as happy teaching what he knows about coffee to anyone and everyone. (He also won a world barista championship back in the day, too.) I daresay he’s even got me into coffee.

Personally I like Hames Joffman a bit more, but he's not posting as frequently any more.

Jokes aside, another endorsement from James. He's an absolute coffee weirdo, and he knows it, and he embraces it. The equipment and ingredients that he buys is so out of touch with my reality it can't even compare, yet I watch his videos.

I like his content because he does not take himself seriously, which is always a good sign to me. And because he's very pragmatic. Even though he takes snobbery to the next level, he will always sniff at a new product if it is complicated to use, because like me, his primary need for coffee is to overcome morning grogginess, and he does not want to faff about during that time.

I also like James Hoffman, a little bit more, a little bit less? I don't know.

Even his review of toy coffee machines[0] had me watching with full interest. This guy can sell you anything, but I think that is also part of being a barista?

[0] https://www.youtube.com/watch?v=5OFt2T8aH9I

Yeah, that's cool. As someone who fell down this rabbit hole well over a decade ago, complete with a history of my own large storage bins for green beans, multiple roasters, thousands spent in makers, etc... Yet, today, my most used preparation methods are an AeroPress or a Chemex pour over, albeit with hand-ground beans that a friend and neighbor roasts... I just don't think I want to hear 2 minutes of useful information from watching 25 minutes of videos (between the 2 that are linked here).

The video on how he won it is very good and probably would be interesting for any competitive sport or craft. Recommend that.

Nile Red demonstrates removing caffeine from tea here:

https://www.youtube.com/watch?v=RIbff5iD0GQ

and from coffee here:

https://www.youtube.com/watch?v=_CoxEgbyeK4

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.

Surely it must also extract some other stuff. I wonder what the extracted stuff tastes like (minus the CO2 of course)

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 stumbled upon an interesting discovery. Zosel, like many other chemists, was using high-pressure C02 to remove individual substances from other mixtures."

It must have something to do with caffeine being an alkaloid, while coffee overall is acidic. So I suspect that this pressurized CO2 is able to dominantly remove such alkaloids... I leave the details to a chemist :)

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

But the parent comment is about CO2 decaffeination specifically, not decaffeination in general.

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.

The way this author[0] took complex scientific processes and made them understandable to someone without a science background is admirable. I want to try and emulate this when I write for non-technical audiences.

[0]https://miamioh.edu/profiles/cas/michael-crowder.html

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.

Besides that if the caffeine-free variants were to spread in the wild and cross-breed with regular coffee that would be disastrous.

From comments it seems caffeine-free plants already exist.

Wouldn't the cross-bred wild coffee just fall prey to insects more often and diminish competitively?

Maybe. But with very high pesticide use nearby maybe not?

On HN only the other day in a discussion about caffeine and coffee consumption I pointed out that caffeine was one of the more innocuous toxins plants use to protect themselves against insects—innocuous to humans that is, there being many more that are very much more toxic to humans.

What I've never seen quoted is a comparison of caffeine's toxicity to insects compared with other common plant toxins (pyrethrins, terpenes etc.) and whether its toxicity is aimed at insects that specificly attack coffee beans.

As far as I'm aware caffeine isn't used as an insecticide whereas pyrethrins are commonly used (but both have comparatively low toxicity in humans). Why I ask is that pyrethrins are effective against a broad spectrum of insects, that caffeine isn't used could imply its action is narrow and only targets a specific species of insect.

No doubt this info is buried somewhere deep in the scientific literature and or within pesticide manufacturers' papers but it's curious it isn't common knowledge given the ubiquity of caffeine.

Perhaps those in the coffee business don't want it known in case it affects business. :-)

Not sure, there's a comment below my parent comment that indicates that there's wild caffeine free coffee. it just tastes bad apparently.

Thanks. I don't drink decaffeinated coffee not because I don't get any effects but because of its tase, which I reckon is horrible. Caffeine is bitter (well slightly so) and I reckon removing it makes it unpalatable for me, it's likely why caffeine-free tastes bad. (I'd add I drink both coffee and tea without milk or sugar, that'd make the taste of the caffeine more noticeable I'd reckon).

Incidentally, I was unaware there is wild coffee sans caffeine.

I would recommend trying it, its not as bad as you say it is

OK. This is off topic a bit but it's like this: I don't much like tea or coffee—except when they're very good. But anyway I drink both and that includes really bad stuff—with one exception, I will not drink either with milk/cream or sugar. I'll tolerate maybe a single teaspoon of sugar in coffee but any sugar in tea I find repulsive and just won't drink it. So, decaffeinated coffee falls within the range of 'acceptable' beverages I'll drink, but I'd prefer the real thing. (I lied a bit there, I also find decaffeinated tea truly repulsive and I never drink it but then it's so rare (at least in my circles) that I never come across it.)

As I said I really enjoy really excellent tea and coffee but I find getting what I like very difficult at a price I can afford. With tea, I used to drink good quality Darjeeling but it's almost impossible to get nowadays (it's over $1,000/kilo). Adding anything to that except perhaps a slice of lemon would be a crime. The cheap stuff that's now sold under the name is little more than tea dust, a good cheap Orange pekoe is a much better deal. I also love good green tea but again the only way I can guarantee to get what I want at a reasonable price is in the tea markets in Japan and I'm not there very often.

Similarly, truly good coffee is also very difficult to get, and it's fiddly to prepare. Even with good beans and an espresso machine I'll more often than not make a suboptimal brew.

I've this theory that many people who add milk and sugar to tea and coffee do so to mask their bad quality although they're not necessarily aware of the fact as it's so rare to get truly good product.

Incidentally, I was introduced to tea somewhere about 4/5 years of age when my mother gave me a weak brew with milk and sugar. I recall that about the time I started school telling my mother to stop putting milk in the tea, the following week I told to stop adding sugar. I've taken that way ever since.

It can have a bit of a taste yeah, but I found mine and I'm sticking with it. Have both with and sans and they are quite good (if anyone's from Germany and wanna try: Brazil mild decaf from Tchibo, actually really good)

"Have both with and sans…"

Not from Germany so it's not available where I am (or perhaps it's not common).

You say it can have a bit of a tase but was it notably different to the caffeinated one? Reason for asking, I've not compared the two types from the same company together to get an objective comparison.

Not sure of the current progress with breeding and cultivation, but there is a naturally occuring caffeine-free coffee plant. https://en.m.wikipedia.org/wiki/Coffea_charrieriana

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)

Have you looked into L-Theanine? It’s an extract from green tea. I add it to my coffee sometimes and it smooths out the experience

Do you put sugar in your (decaf) coffee? A lot of energy comes from sugar.

I had a similar problem. Coffee, decaf, even dark chocolate would be very stimulating and would mess with my sleep, even a single cup in the morning. I tried quite a few things to solve this and ended up discovering that supplementing with molybdenum solved it. Molybdenum is an essential element important in the metabolization of some compounds, including caffeine. It's cheap and may be worth trying.

Also, I found that L-Theanine helped but only for maybe a week or so before it became less and less effective. For me, it was obviously a band-aid solution that wasn't correcting the underlying problem.

I couldn't find any citations that mention molybdenum as a way to increase metabolism of caffeine. However, I found one reference [0] that mentions, "Consumption of broccoli and brassica vegetables in general and absorption of large quantities of vitamin C increase caffeine clearance".

EDIT: It would seem that the vitamin C paper [1] concludes the opposite of what [0] states. "These results indicate that the elimination of caffeine in the elderly is not affected significantly by the concentrations of vitamin C achieved during this study."

    [0] https://www.coffeeandscience.org/health/coffee-and-caffeine/caffeine-and-metabolism
    [1] https://pubmed.ncbi.nlm.nih.gov/7064899/

A limited number of studies suggested tobacco smoking increases the metabolism of caffeine, an effect possibly mediated by caffeine.

"Caffeine metabolism is increased by smoking, an effect mediated by an acceleration in its demethylation (it also increases xanthine oxidase activity) (Parsons and Neims, 1978). Smoking cessation returns caffeine clearance rates to nonsmoking values (Murphy et al., 1988)."

https://www.ncbi.nlm.nih.gov/books/NBK223808/#:~:text=Caffei....

I'll add some more info to my post.

Caffeine is a purine (https://en.wikipedia.org/wiki/Caffeine).

A Google Scholar search for "molybdenum purine" will come up with many studies discussing how molybdenum is involved in purine catabolism. For example, the following article states "[molybdenum] is considered essential because it is part of a complex called molybdenum cofactor that is required for the three mammalian enzymes xanthine oxidase (XO), aldehyde oxidase (AO), and sulfite oxidase (SO). XO participates in the metabolism of purines". (https://aspenjournals.onlinelibrary.wiley.com/doi/abs/10.117...).

When I was younger I was able to drink multiple pots of coffee in a day and even drink coffee right before going to sleep without any obvious issues. So when I couldn't even drink a single cup of coffee in the morning on a regular basis without problems I had reason to believe there was something wrong with me and it wasn't simply a genetic quirk.

I find discussion about caffeine sensitivity in humans rather fascinating given the very broad range of the amount required to induce an effect.

If those above are to be believed (or not suffering a psychosomatic response) and are still affected by decaffeinated coffee then the dosage between different individuals for given psychotropic effects to occur could be as high as 100:1.

As someone who can drink copious nubmers of cups of coffee in a single sitting and notice very little effect I'm curious to know why this range is so wide (heaven help patients, doctors and pharmaceutical manufacturers if all drugs had such a wide range).

Whenever I raise this the common retort is that I've developed a tolerance to caffeine, and no doubt that's true to some extent. But from experience it's pretty limited, I've been in situations where I've not had caffeinated drinks for months and not noticed any difference when I returned to them. Also, decades ago when I was a student I took up coffee to help stay awake whilst studying and it was pretty inefective. I tried evey strong brew availabe including up to five heaped teaspoons of Moccona instant coffee per cup and it was like water off a duck's back—almost useless/inefective.

The question is why do some people have a supersensitive response to caffeine whilst others do not.

There are stimulating compounds in coffee other than caffeine, so I've pondered that people who find decaf stimulating may be reacting to some of these other compounds.

Another consideration is that people seem to often report that coffee is more stimulating than caffeine pills, even if the amount of caffeine is similar.

"There are stimulating compounds in coffee other than caffeine,…"

OK, that makes sense and I'm not surprised. I claim no expertise in coffee chemistry but I'd guess there'd likely be small amounts of other xanthines including xanthine, theophyline, theobromine [we ought to stop using that confusing name] and perhaps others. Are you referring to these or another class of drugs altogether?

You know, your mention that others report coffee more stimulating than caffeine pills got me thinking. As I said in my other comment, caffeine did little for me when I was studying, heaps of instant coffee made very little difference. I'd not mentioned it but I'd also tried OTC caffeine pills and they were pretty useless (and instant coffee was cheaper).

Now to an interesting connection you've just reminded me of. Some years after I'd finished studying (trying to stay awake with caffeine), we used to frequent a little French restaurant that served an unusual type of coffee that I enjoyed very much.

Being a frequent customer I asked the owner what type of coffee he was serving and he told me it was a special New Guinea blend that he'd specifically selected for the restaurant.

Now to the interesting part: as I said, many cups of caffeine-laden coffee have little effect on me but this coffee was something else altogether. Within a short time of consuming a cup or two I'd get a sudden urge to urinate, similarly my partner and the coffee had an even stronger effect on her than it did me. This wasn't an isolated case, it happened whenever we went to the restaurant, in fact we used to joke about it.

I need to add that I've always had a pretty good bladder, for example I've crossed the Pacific from Los Angeles to Sydney numbers of times without needing to use the restroom. So there was something rather unusual about that coffee. It's only a guess but I'd reckon it likely had much more than the usual trace of theophyline in it. Perhaps there were much higher levels other xanthines as well.

Hum, now I'm wondering whether these methylxanthines can act synergistically when in certain combinations/ratios. If it wasn't one or more of them in combination in that coffee then I wonder what other drug could have caused the strong diuretic effect.

Thanks for you point, it's made me think.

I'm no coffee chemistry expert either, but the following article indicates that the main adenosine receptor antagonists are caffeine, theophylline, and theobromine, all of which are found in coffee, tea, and chocolate (https://en.wikipedia.org/wiki/Adenosine_receptor). These three are all considered purines and therefore molybdenum would be involved in breaking them down. All three also have a diuretic effect (1) and Theobromine "shows strong diuretic effects" (2). That leads me to wonder if the ratio of these three varies significantly between coffees. I'm not sure but found one paper that shows that it does in cocoa (3), so perhaps it does in coffee also (there's probably research on coffee about this and I just didn't look hard enough).

(1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4383091 (2) http://medical-technologies.eu/upload/1.effects_of_coffee_al... (3) https://www.sciencedirect.com/science/article/pii/S030881460...

Thanks for the references. Just had an initial look and I'll return to them shortly. I was already aware the action of xanthine class drugs is centered on the adenosine receptors but I've little deeper knowledge of the subject, drugs and their biological action isn't my field so I'll have to take the documents slowly.

However, I've already noted in (2) a statement under Theobromine that it's a strong diuretic. That's interesting but what does strong mean here? I dislike simple-notion words in papers unless they're quantified (they require numbers against them).

That said, that's not a criticism of the paper having just glanced at it, and it has lots of other interesting stuff I'll need to read in detail. What's particularly relevant about the theobromine entry is this mention of the molecule's strong diuretic effect. When I made my point towards the end of my comment that that particular coffee 'likely had much more than the usual trace of theophyline in it', I deliberately left out reference to theobromine because I'd seen references that it was biologically less active than either theophyline and caffeine.

What was implied was that when evaluating the effects of coffee that theobromine was essentially considered irrelevant because it wasn't as biologically potent as either theophyline and caffeine and that its concentration in coffee is considerably lower than either of the other two.

Perhaps the earlier reference (which I've to locate again) was referring to theobromine's psychotropic effects rather than its diuretic effects. I'll now have to review and revise my understanding of common xanthines to correct my misunderstandings.

As someone who's not professionally involved in this field I sometimes think I'm a little mad for allowing my curiosity to get the better of me. :-)

Did taking molybdenum improve metabolism of caffeine in your case?

Did you have blood markers checked? For me, some values like GPT/GGT are in fact increased for unknown reasons.

I recently and unsuccessfuly researched ways to participate in studies, as I'd like to understand why I can't eat chocolate or drink coffee anymore.. I'm slightly concerned other toxins wouldn't be metabolized as well either, leading to early cancer down the road.

I took 1 mg of molybdenum daily for about 3 weeks and then tested out drinking coffee. By this point I had tried many other interventions that did not help. I wasn't expecting the molybdenum to help but figured it was worth a shot since it was about $6 for a bottle. After the fourth day of drinking coffee, it was clear that something had changed; the coffee was no longer the issue that it had been. I'm now able to enjoy a regular coffee in the morning without any negative issues. I didn't change my diet or supplements during this time or anything else I can think of that could possibly have contributed to this change.

When I was sensitive to coffee I felt just wrecked and exhausted by the coffee. I couldn't sleep well at night. Several days in a row of drinking one coffee in the morning and I'd get to the point where I would wake up feeling jittery the next day. Now, this is completely resolved.

My blood tests for commonly tested health markers such GPT and GGT have always been fine and tend to be tested about once a year. I had the coffee sensitivity for quite a few years until recently when I finally resolved it.

I do have some minor gut issues, so I'm guessing this is to blame for any nutritional deficiencies (I eat a healthy diet of "real" food).

Thanks a lot! Just ordered a bottle and will give it a try

Stopped here to say L-Theanine as well. It's part of my morning routine for years now and without it coffee turns literal poison for my nerves.

Very interesting suggestion, will look into it. L-theanine has long been a staple of mine to counteract the effects of coffee. Typically have to redose at 4am, as the cortisol spike keeps me awake otherwise (that is, from a small coffee 26hrs ago..)

These days I'm limiting my intake to once a month or so

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.

Everybody is different. I'm sensitive enough to caffeine that trace amounts causes anxiety. I have to avoid chocolate.

I'm equally sensitive to alcohol. Because it's immediately absorbed into the blood, a sip of scotch will take out my antidepressant in seconds. It's shocking how quickly and how severely even a small amount of alcohol affects me. It's almost like an allergy.

it might be easier to just artificially recreate "natural coffee flavor" than to try to remove everything

That's exactly what I'm doing by drinking barley coffee. With some milk and sugar it's getting close to coffee (minus all the aromatic flavor)

I quit caffeine a decade ago and am an evangelist for doing so; garbage drug. I'm very sensitive to it, and it absolutely wrecks my sleep. But I drink like five cups of black decaf every morning, which probably works out to 10-20% of the caffeine in a normal cup, and am pretty much fine. There's enough caffeine in decaf that I'd be afraid to drink it after 2PM.

I had to greatly reduce my caffeine intake at one point, and I've kept it down since. I'm inclined to agree that it's a garbage drug, but in small amounts and strictly in the morning work -like you do- it seems to work for me. Rather than drink 5 cups of decaf I drink one cup of decaf made with 6 parts decaf beans to 1 part caf. Then maybe later in the day I might eat three tiny pieces of 100% chocolate mass, but like you I'm afraid to after 2PM-ish.

I’m a big advocate for replacing coffee with cacao. I drink it in the morning instead of coffee. Made from raw cacao paste and hot water, I use an immersion blender to mix it well and then add half and half for flavor. Way more nutrients than coffee and the theobromine is much gentler than caffeine and lasts all day.

Huh! Gonna have to try that!

Watch out for the lead and heavy metals and cacao https://www.consumerreports.org/health/food-safety/a-third-o...

Ah yes, there's that. Bah.

Excellent to be concerned about heavy metal exposure. Cacao typically contains lead and cadmium; the reference dose (usually defined as: The amount of a chemical a person, including sensitive groups, can be exposed to on a daily basis over an extended period of time (usually a lifetime) without suffering deleterious effects.) of lead according to EPA is 3.5 ug/kg/day and cadmium is 1 ug/kg/day. The cadmium content of cacao nibs/paste is usually 0.5-1 mg/kg and 0.025 mg/kg lead. So cadmium is the one to be concerned about here; for a 100 kg person, the RfD would be 100 ug or 0.1 mg of cadmium per day. The FDA defines the toxicological reference value for cadmium as 0.2-0.3 ug/kg, or 20-30% of the EPA's RfD. 100 grams of cacao at the high side, 1mg/kg would contain 0.1 mg of cadmium. So a daily dose of 1-2 gram of cacao per kg of body weight should be within the RfD, and 0.2-0.6 grams cacao per kg body weight would be within the TRV. It should be noted that root vegetables such as potatoes and beets also tend to contain cadmium at a rate of about 1/10 per weight compared to cacao, but I would find myself just as likely to eat 500 grams of potato or beet vs 50 grams of cacao, which would net the same amount of dietary cadmium.

So definitely don't overdo it on the cacao and eat hundreds of grams per day, but IMO no reason to avoid it completely, relative to other vegetables that can accumulate cadmium. This is not medical or dietary advice.

> I might eat three tiny pieces of 100% chocolate mass

Do you mean choco-nibs? love these, and they are great for adding crunch to things.

Chips, not nibs, but 100% cocoa mass.

> I quit caffeine a decade ago > I drink like five cups of black decaf every morning

You didn't really quit caffeine, you lowered intake.

It's mostly genetics. Some folks should never have any amount of caffeine, while others it hardly affects. I have the hardly affects gene.

So, in the Swiss Water process, caffeine-free coffee is made by soaking the beans in... caffeine-free coffee?

(My initial though was, "then how do you get the cafeeine-free coffee in the first place", but I see the answer is that you can decaffeinate liquids by running them through charcoal filters... something you can't do with solid beans.)

I wonder if instant decaf is more effective, as you skip a step to pour your coffee cup.

Just get a venous catheter installed. No sense in all this pouring and crockery.

I love decaf but the main problem is how fragile the stability of the beans are. They go bad quickly. To get the same cup of decaf coffee every day requires more work if you are grinding your own and making espresso. Still, I love them.

Personally, I've found the CO2 method to have a lot more flavor than the Swiss Water. I also found the CO2 beans don't deteriorate as quickly as the Swiss Water beans.

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 usually rather fresh.

Mixing half decaf with regular beans is a great idea, I've been doing that for years. The mix of flavors is good too, if you are brewing filter. You can get away with a lot more when you do filter.

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.

I hunted around for good decaf espresso beans for a couple years and then someone recommended local own-brand supermarket beans, 9.50e/kg and I've had some better tasting extractions than a lot of artisan expensive regular beans I've bought. No roast date, so who knows how old, but a good consistent cup until bag empty.

What I also then noticed was that a lot of the coffee houses here use an inferior grinder for their decaf, smaller burrs, and/or the older hopper based grinder vs on-demand for their regular beans. No wonder it gets a bad rep.

Anyway I was quite amazed to suddenly find myself enjoying decaf so much.

I keep my decaf beans frozen. That seems to help a lot.

SWP is trendy and "chemical-free" but in my experience every decaf made with it is lacking something. C02 is neutral. EA is probably the best for fruity coffees.

I agree. SWP coffee usually has a very flat profile to my taste. EA is far and away the better processing method.

I find the ethyl acetate processed to be the better of the decafs. It's my go to these days.

Why not try low caffeine variety like Laurina? It's about 1/3 to 1/2 the caffeine of Arabica.

TIL about one of the solvents involved, ethyl acetate, and the fact that it is not good for you. How do I know that my local coffee shop's machine is working correctly and provides only safe levels of this solvent?

It smells like nail polish remover, well nail polish remover with the acetone subtracted, and it is noticeable well below any toxicity threshold. It's also a characteristic component of some fruit / fermentation aromas

I wouldn't expect a coffee shop to do the decaffeination there. Rather, the company that does the decaffeination is its own thing, which then ships their product to the roaster, which then ships their product to your local coffee shop.

Also, if you're buying fancy coffee, chances are it's Swiss water process, for better or worse.

Worse? You mean in comparison to the CO2 one, which I hadn't heard of before?

My understanding of the consensus is that it favors EA decaf.

how did you get that from the article?

"One of the common solvents, ethyl acetate, comes naturally in many foods and beverages. It’s considered a safe chemical for decaffeination by the Food and Drug Administration."

speaking from a chemist's perspective, ethyl acetate is basically non-toxic. it decomposes into ethanol and acetic acid (vinegar). dcm (methylene chloride) is toxic, but should be completely removed before it ever reaches you. the nice thing about volatile organic solvents is that they're...volatile, so they are easily stripped from coffee beans.

There's probably more ethyl acetate in apple juice (it occurs naturally in fruit) than there is in the equivalent quantity of coffee. Because people freak out when they hear terms like "ethyl acetate", the industry has started calling this "sugar cane decaf".

Ethyl acetate occurs in nature and breaks down into ethanol and acetic acid in the body. It has a very low toxicity in the levels encountered in coffee.

Local coffee shops won't do the decaffeination, that's usually done by the roasters before it gets to the shop.

It'd be interesting to compare these 3 methods side by side starting with same beans.

I've tried, conservatively, a dozen and a half of different decafs available here in the EU, and some a markedly better than others. In fact, most are outright garbage with an exception of two that are virtually indistinguishable from each other even though they are from unrelated brands. So I wonder if the differences are due to the process rather something else.

Can you share which you found the best?

Lavazza and Kimbo.

I thought about buying a supercritical CO2 extraction machine from Alibaba and having a small business around making decaf beans for roasters, but the numbers didn't work out great. I believe it was around $20k usd for the medium sized ones.

Is this written up anywhere? I.e. anywhere that walks thru a sample business model?

Well it's not too complex. Say $25k for the machine amortized over 5 years is about $400/mo. Let's say $500. Cost of goods would be around $7.50/lb for some nice unroasted beans. Let's say you sell for $10/lb. Fixed costs would be rent ($5k?), utilities (1k?) and whatever other costs to package etc. not even touching salaries. So at $2.50/lb revenue you'd have to process and sell 2,400 lbs per month just to break even on fixed costs. That's a lot...

Well, they used some unhealthy solvents to extract the caffeine in the past. Swiss water method should be ok, but I just don't trust that some cheap company is not cheating in the process every now and then.

I drink regular coffee.

Why are there no GMO decaf bean varieties? Is the caffeine really that necessary for pest control even when cultivated/farmed?

Does it work the same for instant?

Instant coffee is "just" freeze dried coffee. You make "normal" coffee, and then freeze dry it (and then usually you process the results to get nice shaped lumps instead of randomly sized flakes and powder). I say "normal", because you will get flavor loss/changes in the freeze-dry process, so you'll want to brew with that in mind.

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.

Will an entrepreneur please make high quality (great tasting) decaf coffee ubiquitous?

There's a growing anti-drug sentiment that should be a great tailwind.

It's hard for me to find as good tasting a bean as it is with non-decaf. I've tried subscription services or pay huge shipping and product premium from some boutique retailer, the beans are always just ok. Decaf still doesn't get enough priority as the product itself, always an afterthought it feels like.

It can't ever taste the same as caffeine has flavor.

I don't think people necessarily need it to taste identical. It just needs to not taste like ass.

It has a sharp, very bitter flavour most people hate. It's unlikely caffeine is contributing positively to the taste of anything.

I'm not sure what your standards are, but I'm not sure if this is even possible.

I drink Stumptown which I grind at home for my espresso machine -- their caffeinated Hair Bender blend in the morning, and then in the afternoon I'll often have their decaf Trapper Creek (Swiss water process) on the days I don't need an extra jolt.

It tastes perfectly great to me. Maybe my palette isn't refined enough.

But decaffeination is always going to alter/remove flavor somewhat. So if you've tried high-quality versions like Stumptown and find them lacking, I'm not sure it's even chemically possible.

(Also I'm not super clear -- have you found high-quality decaf and you just wish it were more common? What brand(s) are high-quality? Or you haven't found it, and you're complaining that they're all "just ok"?)

The gold standard for this in sensory analysis is a triangle test — which I happen to have done with coffee from Ninth St Espresso, who sells a regular and substantial identical decaf. We brewed 3 identical batches (where 2 were the same beans and the 3rd was the other bean). In an office with ~12 tasters, the ability to pick out the “different” beans was 33%… ie random chance.

If the above sounds confusing, consider red wine vs white wine… visual inspection alone would get you 100% accuracy.

I used to believe decaf processing would have to change the taste, but empirically, with admittedly untrained tasters (but ones who know coffee very well), we couldn’t tell.

Decaf is simple to pick out by a person who is competent at tasting coffee. As easy as your red/white wine visual test. People in general are very bad at tasting and especially thinking and communicating about tasting. Plus also people may not know what decaf coffee tastes like or may have never thought about it before.

There was a recent lifestyle article about decaf coffee. Have you tried any of the roasters listed here?

https://sfstandard.com/2024/07/15/decaf-coffee-is-finally-wi...

I am not in SF, and so I've never heard of any of those roasters.

Beanfruit generally ranks as one of the decaf favorites online. You should check it out.

Good example of what I mean:

They offer 7 different coffees. Only 1 is decaf! As if it were a "flavor"

The decaf process matters, a lot.

Even great regular coffee isn't ubiquitous yet.

It will depend on your taste buds but I find that in bean form you can get reasonably good decaf coffees. Try a local roaster and one that was roasted 1-2 weeks ago or so. In instant it is very hard! This one is alright: https://www.republicaorganic.com.au/products/organic-decaf-i...

I'd like to talk a bit more about the cheapest and most common process here. They state that ethyl acetate is below the FDA limits and therefore safe. For a start ethyl acetate is still pretty bad but it's not the cheapest.

Another common solvent not mentioned here is Dichloromethane. It's a pretty clear cancer causing agent https://www.reddit.com/r/todayilearned/comments/pr8k9v/til_s...

You know what else is a solvent for decaffeinating coffee? Benzene. https://en.wikipedia.org/wiki/Benzene#Health_effects

Don't drink decaf. The CO2 method is pretty safe but the simple fact is unless you're sure how your beans were decaffinated you're better off not drinking it.

The reddit post mentions that DCM is evaporated and it is basically not present after the process. Actually the thread mentions that all the fuss like your post is mostly scaremongering without actual understanding the mechanisms. Do you have evidence that indeed the phase change and separations may not happen?

"Basically" and "mostly" undermine your assertion.

My thought is: if the process is followed properly there is very little risk of these chemicals being in the end product, but if a mistake is made, they could be present in levels that may have some negative health effect. However, if the water or co2 processes were screwed up, the only risk is caffeine being present, which is not ideal, but not as bad as those chemicals. We all know mistakes happen, which is why I'd rather go with a process that has less negative outcomes from a mistake.

This reminds me of a reddit post from about 10 years ago where people started to notice that when they get decaf coffee at work it sometimes bleeds through the styrofoam cup while the regular coffee never does. There have been several other reports of this since. The most credible theory was that sometimes there is solvent left over after the decaf process:

https://www.reddit.com/r/mildlyinteresting/comments/2m2fiy/o...

It's been a hot minute since I've seen a styrofoam cup in the wild.

Ya, the styrofoam is almost as shocking as what this solvent might be doing to the bodies of those who drink it.

Do you have evidence that solvents remain in the coffee in significant levels? They're highly volatile so this seems unlikely.

Provide actual links to research or everything you say is fear mongering.

Benzene hasn't been used in decades. See this for information about solvent decaffeination:

https://www.compoundchem.com/2018/09/26/coffee-decaffeinatio...

Earlier this year dichloromethane was banned in the US for all but a handful of uses, so producers who used it in the recent past will not be able to any more:

https://www.epa.gov/newsreleases/biden-harris-administration...

Decaffeinated coffee and tea are, I believe the only food products allowed by FDA even a trace amount of dichloromethane (methylene chloride) in them. It's not allowed in cosmetics either.

I came across a startup once using it as the solvent in their liquid bandage product though because 510k clearances are a fucking joke.

> You know what else is a solvent for decaffeinating coffee? Benzene.

Please don't spread misinformation. Benzene was the original solvent used 120 years ago in Germany when decaf was first invented. It did not last long as the dangers of benzine became apparent. There have been several generations of solvents used in the over one century since then and benzine has not been a part of the decaf world in a very long time.

> Don't drink decaf.

There is no reason not to drink decaf and recent studies have found it to be just as beneficial as normal coffee for antioxidant properties. Coffee in moderation is good for you, caffeine or not.

"Coffee in moderation is good for you, caffeine or not."

As I pointed out in another post a few days ago we consume many plant products that contain chemicals and toxins that are harmful some of which are very toxic yet we do not remove them from our food.

Plants especially make these dangerous toxins to deter or kill insects that eat them, I went on to point out that caffeine is one of the most innocuous of these toxins and that some common ones are considerably worse.

In a response to a poster who quoted the negative effects of different amounts of caffeine from Wiki (1-1.5g and >5g respectively) I then listed a comparative scaling with a toxin found in the common vegetable spinach, specifically oxalic acid. To quote:

"…If you scaled up oxalic acid daily doses in the same ratio as for the caffeine example then in the first instance the person would almost undoubtedly have kidney stones. In the second example the person would be dead. Right, at that dose Popeye's spinach meal would almost certainly have killed him.

At least the 'caffeinated' person, whilst off his head, would likely be still alive."

The reason why we remove caffeine from coffee is twofold, the first is that it's comparatively easy to do so when compared with toxins found in other foodstuffs (for instance, to remove mercury in fish would be inordinately difficult); the second is that caffeine has noticeable psychotropic effects that manifest shortly after consumption and that they are obvious worries some people to a considerable extent while others enjoy those effects—and many even depend on them to start their day.

Thus, as with alcohol, caffeine has both strong emotive and sociological aspects to it. It's why caffeine features high in popular culture, everyone knows of and talks about its effects.

On the other hand, despite the fact that it's dangerous and that its toxic effects are dire and insidious, oxalic acid is hardly ever mentioned in popular culture specifically because its effects are not as immediately obvious as those of caffeine. As they take a much longer time to manifest than those of caffeine, it's much harder to draw a connection between them and their cause.

Moreover, it's rather ironic that the popular cartoon character Popeye came to prominence because of a principal property of oxalic acid, its extreme bitterness. Oxalic acid's bitterness contributes to the taste of spinach and kids find it strong and overpowering because of their immature palates. So Popeye making fun of kids who don't eat spinach seemed a good strategy to get them to eat it (I've no idea whether the strategy worked as I liked spinach from when I was first introduced to it).

In small doses oxalic acid can be consumed reasonably frequently without harm as it's in many of our common vegetables, although that's not necessarily so with all vegetables such as spinach, rhubarb and beetroot which contain it in much larger amounts. Consumption of these vegetables in large amounts or even eating them frequently can lead to adverse effects such kidney stones. Also, the acid's oxalate metabolites are very insoluble and form crystals that can actually damage the kidneys.

(I have a two-kilo container of oxalic acid which I use to remove rust from tools and to bleach stains from wood and it's very conspicuously labeled 'Poison' in big letters.)

You say caffeine is not good for you, which implies it's dangerous. As I've shown I reckon the evidence supports my position that it's not as dangerous as many other toxins that we encounter in our food, like it or not we have to consume them to stay alive.

Chemical technology has given many the choice whether or not to consume caffeine but I'd venture it does not give them the right to criticize or single it out over and above the many other toxic molecules we unavoidably encounter on a daily basis.

To do so is not only counterproductive but also it's not in the best interests of others, it also shows that one is misinformed.

BTW, the solubility of caffeine in benzene is poor when compared to other better alternatives, it's another good reason not to use it for the extraction process.

Moreover, nothing I've said above applies to benzine, it's a nasty, dangerous compound to be avoided. That said, it's a curious phenomenon why so many useful compounds contain benzene rings many of which aren't toxic—even life depends on the benzene ring. Nevertheless, others based on the ring are so dangerous that they leave benzene's toxicity for dead.

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