I have a container of ground coffee which is unlabeled. I can only drink decaf right now, though.
Is there an easy way to tell if the stuff is decaf or not? I’m hoping there’s some “kitchen trick”, sort of like how you can tell if an egg is hard-boiled or not by spinning it, stopping it abruptly, and seeing if it spins a little by itself when you let go (because the liquid innards continues to spin). Something clever like that.
Anybody know a way to determine if it has caffeine that doesn’t involve drinking it?
Doctor, I’ve got some unlabeled sausages hanging from the rafters. Is there an easy way to tell if they contain PORK, cuz you say I can’t eat PORK, so, uh, is there?
My guess is “no”–not without a chemical assay. And stop ingesting unlabeled substances!
Caffiine has (to me) a distinctly bitter tang or “sharpness”. Decafe coffees taste “flatter” in this regard, but you can’t really tell this without tasting some. Toss it and buy decafe to be safe. There some acid loving plants that love coffee grounds mixed into the soil.
I was hoping a chemistry major out there could describe a simple test for the presence of caffeine, with household substances, but I guess that looks like it’s not to be.
Caffeine is a methylxanthine, and its chemical structure is rather similar to some of the nucleotides in DNA. I’d say it was very unlikely that any ‘kitchen’ chemical test could distinguish between caffeine and roasted DNA (e.g. coffee beans)
HOWEVER, there is far more caffeine in coffee beans than DNA or any other similar compound, so it would be possible, in principle, to discriminate them through simple UV absorption at the nucleic acid band (a very high reading would suggest caffiene, not nucleic acids), or with greater accuracy at the so-called “blue band of caffeine” (actually IR, ca 2420 nm). It can be done, in the kitchen, with materials many households -and scientifically inclinded children- may have, but it’s pretty much another case of “If you have to ask, you can’t.”
The poster who suggested a trial on another person probably isn’t far off. Pets work too. Alas, urine screens are expensive, or I’d suggest that.
Realistically? Money may be tight, but you’d have to have a lot of unidentified ground coffee to matter in the long run. Besides, I’d call it a “life lesson” – what the heck are you doing owning unlabelled caff/decaf coffee anyway? There’s no excuse for that. Everyone should think of them as two different things, not two “flavors” of the same thing – as different as sugar and “nonutritive sweetener” in a diabetic household. Either someone who wants caffeine doesn’t get it, or someone who shouldn’t have it gets it. Either way, it’s bad news.
Sorry, it’s almost 30 minutes into the new day, and I haven’t had my coffee yet.
When you say you can “only” drink decaf, you don’t mean the smallest sip of caffieine will send you into pulmonary arrest right? So why not just brew half a cup of mystery beans and use one of the most sensitive chemical assayers present in your kitchen - your tounge.
I’m battling anxiety problems, which the caffeine exacerbates. I don’t need even a half cup’s worth of caffeine.
Besides, I cannot tell the difference just by taste, so my tongue is useless as a testing device. I could drink it and see if I go into an even deeper anxiety tailspin, but I’d rather just keep it until the anxiety is under control.
[hijack] Why drink decaffenated coffee? Isn’t it like drinking non-alcohol alcohol? If it is “for the taste” then surely part of the taste of coffee is caffiene? [oooops sorry hijack over]
Caffeine is in fact tasteless and odourless. A mixture of water and caffeine tastes just like water, not coffee.
In theory, thus, decaf coffee should taste the same as regular coffee. In practice, though, the decaffeination process also removes some of the other components of coffee, hence the change in taste.
If you have coworkers or neighbors, maybe somebody who doesn’t mind if it turns out to be caffeinated would swap you for some “known” decaffeinated. Or for something else other than coffee, or you could sell it to them for half price. Or you could just give it to them rather than throwing it out, for a couple “good will” points.
FWIW, I know an experienced waitress at the local family-owned diner / coffeeshop who can tell decaf by its appearance in the cup. She approached our table one morning, peered in my uncle’s cup, and said, “Looks like you’re drinking decaf” and proceeded to offer the orange coffeepot. When I asked her how she knew, she said “You could skate on that stuff”, ie, it had a really solid-looking surface.
I bet you could use paper chromatography. Do a quick web search for a detailed explanation. The basics you need are:
a solution containing your unknown (the mysterious coffee)
control solutions to serve as standards (ie know decaf and regular)
paper (filter paper; cut up coffee filters or paper towel strips may work)
a solvent (hopefully some organic chem genius will swoop in and suggest one. I’d play around with water, ethanol, isopropanol, and acetone as they are readily available in the home)
a detection method (not sure how one could spot the migrated caffeine on the filter paper. Can anyone think of a colorometric method?)
The principle of this method is that a solvent migrates along a paper strip by capillary action. If a solute is included (in this case caffeine), this too will migrate, ideally at a slower rate than the solvent. The relative rates of migration of the solvent/solute is determined by the the relative affinities of the solute for the immobile phase (paper) versus the mobile phase (solvent). This is reflected in the solutes partition coefficient for a given immomobile-mobile phase system.
With the right solute-solvent combination, caffeine will migrate up the paper a characteristic distance from it’s origin. The standards can be compared to see where the caffeine spot lands. Then examine the experimental to see if there’s a caffeine spot or not.
That’s not true. Caffeine has a sharply bitter taste - in fact, the soda companies claim that that’s why they add it to their drinks. Obviously not true, but they claim it is.
But coffee is bitter enough that it’s probably not easy to tell just from the taste of the caffeine. Decaf does taste different because various other chemicals are leached off as well, but I wouldn’t trust myself to know.
i don’t think brewing a cup for a caffeinated coffee drinker is a good test, false positive is too likely. brewing a cup for a decaf drinker, though who doesn’t experience bad effects, is a better test. if they are more alert and productive then it has caffeine.
