30 second decaff trick debunked


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30 second decaff trick debunked

Postby entropyembrace » Feb 20th, '10, 01:27

I thought this blog post was interesting because it cited recent scientific studies that debunked a couple of common perceptions about caffiene in tea.

Thanks to new data from several studies, the idea that tea leaves could be decaffeinated simply by rinsing prior to brewing is now both outdated and inaccurate. At Art of Tea we are dedicated to providing our customers with accurate information and pride ourselves on being on the leading edge of research. Here are the facts regarding home decaffeination and caffeine levels in different teas:

To begin with, it’s important to understand that decaf and caffeine-free are not the same thing. Caffeine free means that there was never any caffeine in the product to begin with, while decaf means that caffeine was removed from the product, leaving behind small amounts of residual caffeine.
According to tea experts, the “30-second decaf” theory has been officially debunked. Noted tea technologist Nigel Melican, founder and managing director of Teacraft, Ltd. says, “You cannot (despite what some notables in the tea industry believe) you just cannot significantly decaffeinate tea by using a 30 second hot water wash (in fact 30 seconds leaves 91 percent of the caffeine in place – and removes a lot of the antioxidants).”

A 1996 study at Auburn University backs Melican up. According to the study, only nine percent of the caffeine was removed during the first 30 seconds of infusion. The researchers also found that it took approximately three minutes to remove 50 percent of the caffeine, about nine minutes of infusion to remove 80 percent, and approximately 15 minutes to remove more than 96 percent.
A 2008 study conducted by Dr. Bruce Branan, Professor of Chemistry at Asbury College, found that a three-minute infusion removes 46-70% of the caffeine from a cup of tea and that it would take a six-minute infusion to remove 80% of the caffeine.
The conclusion to be reached on the “30-second decaf” theory is thus: it doesn’t work. If you want to enjoy a cup of tea that is truly caffeine-free a Tisane (a fusion of different botanicals) or stand alone herb is your best bet. Art of Tea has an entire section dedicated to delicious caffeine-free blends.

Now, on to tackle the caffeine levels of the four major tea families; white, green, oolong, and black. It’s a popular misconception that both white and green teas have lower caffeine levels than oolong or black teas. The Linus Pauling Institute at Oregon State University conducts micronutrient research for optimum health. They suggest that the popular belief of low caffeine level in White Tea is misplaced: “Buds and young tea leaves have been found to contain higher levels of caffeine than older leaves, suggesting that the caffeine content of some white teas may be slightly higher than that of green teas.”

In 2008 a study at Asbury College corroborates this finding, concluding that white tea does not have less caffeine than green, oolong, or black teas. Likewise, an article in Food research International, Vol 29, 325-330 (1996), states that, “All teas have roughly similar caffeine contents, and one cannot rely on the belief that green tea has less caffeine, as asserted by many popular claims.” So now we know that the myth that both white and green teas have less caffeine than black or oolong teas is just that: a myth.


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Re: 30 second decaff trick debunked

Postby ABx » Feb 20th, '10, 19:17

I don't think the issue is that cut and dried. The Linus Pauling Institute also cites that a cup of green tea has less than black: http://lpi.oregonstate.edu/infocenter/p ... index.html

Something I came to notice a while ago is that the devil is in the details; studies that focus on the leaf state that all types have roughly equivalent levels, while studies that focus on the infusion cite differences.

This isn't entirely unreasonable if you consider what happens in oxidation. Besides chemical differences, oxidation is often achieved by bruising the leaf to let the juices escape, oxidizing while they dry. If you've got all of the juices dried on the outside of the leaf, then the majority of it will go into the first infusion. It's not unreasonable to expect that a tea that yields multiple steeps will have less caffeine per cup than those that wear out after the first steep.

I think the bit in the article I linked above is probably the one that gets to the heart of the matter:
All teas contain caffeine, unless they are deliberately decaffeinated during processing. The caffeine content of different varieties of tea may vary considerably and is influenced by factors like brewing time, the amount of tea and water used for brewing, and whether the tea is loose or in teabags.


The issue is further complicated when you consider that many of the quality greener teas have greater levels of amino acids that counteract caffeine (particularly L-Theanine). Unless you have some susceptibility to caffeine beyond a low tolerance, those amino acids should keep the effects of the caffeine in check.

I think you just have to take teas on an individual basis and consider whether the effects you experience are really serious enough to warrant the effort of finding ways to avoid. The chemical makeup of individual teas and individual reactions to each of those chemicals will be more important considerations than statistics and averages.
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Re: 30 second decaff trick debunked

Postby entropyembrace » Feb 20th, '10, 20:28

You can see the 1996 study at Auburn University and the 2008 study conducted by Dr. Bruce Branan have quite a bit of variation in how long it took to extract the caffeine but neither got anything close to most of the caffiene out in 30s

As for the link you gave there´s a little catch in their results...they prepared the tea according to directions on the package not with equal time, temperature, volumes and weights. Virtually every set of commercial brewing instructions I´ve seen says to use hotter water and longer infusions for black tea and cooler water and less time for green tea so if you follow the package instructions like the Linus Pauling Institute did you´d obviously extract more caffeine from the black tea than the green tea.
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Re: 30 second decaff trick debunked

Postby ABx » Feb 21st, '10, 16:23

entropyembrace wrote:You can see the 1996 study at Auburn University and the 2008 study conducted by Dr. Bruce Branan have quite a bit of variation in how long it took to extract the caffeine but neither got anything close to most of the caffiene out in 30s

As for the link you gave there´s a little catch in their results...they prepared the tea according to directions on the package not with equal time, temperature, volumes and weights. Virtually every set of commercial brewing instructions I´ve seen says to use hotter water and longer infusions for black tea and cooler water and less time for green tea so if you follow the package instructions like the Linus Pauling Institute did you´d obviously extract more caffeine from the black tea than the green tea.

Right; how much caffeine is extracted during steeping is going to vary widely between teas and how they're brewed. (When I said that it's not cut and dried, I was talking about caffeine levels, not your article.)

How much it's actually worth trying to decaffeinate is another question all together. A big part of my point is that you're much better off trying different teas and considering the actual effect you get. If a tea does more to relax you -- even if it does make you a little more alert -- then is it really worth worrying about the caffeine at all?
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Re: 30 second decaff trick debunked

Postby Wh&yel-appr... » Feb 24th, '10, 01:45

entropyembrace wrote:You can see the 1996 study at Auburn University and the 2008 study conducted by Dr. Bruce Branan have quite a bit of variation in how long it took to extract the caffeine but neither got anything close to most of the caffiene out in 30s.


Yes debunks a myth, if u believe those myths :p. However I find fault in the artoftea blogging style, when they fail to link to the full articles they use as reference to make C&P quotes. Hate that, cause any study can be skewed/misrepresented in such form.

entropyembrace wrote: so if you follow the package instructions like the Linus Pauling Institute did you´d obviously extract more caffeine from the black tea than the green tea.


If you read the full article as it should have been linked to, you get a whole bushel of more info :D, to help with your own understanding.

Take Gong Fu style, the way Imen does it (or did it, haven't had her teach me the 'new' way from her trip to China recently) it's oolong, near boiling temp, guestimated 15s infusions. You get a lesser/milder extraction that way, and would *assume* lower levels of caffeine spread out over more cups. She'll do upwards of 15 infusions.

Links to articles...and my snippet :p

http://www.elmwoodinn.com/about/caffeine.html

If your doctor is asking you to cut caffeine completely out of your diet, you should switch to a commercially decaffeinated tea or a caffeine-free herbal.


^...or you could risk it for better flavor, and estimate amounts of caffeine, and just drink the later infusions, give the 1-3rd infusion to someone else, or dump those on some plants :mrgreen: .

Nigel knows how to manipulate the caffeine content of tea bushes–both in the field and in the factory. He claims that several factors help determine caffeine content in tea. It begins with the propagation of the bush. Plants grown from seeds can produce twice as much tea caffeine as clonals. The addition of nitrogen fertilizer can add another 10% to the normal caffeine level. Caffeine also varies by the picking season. Teas plucked in cooler weather might produce less caffeine than those harvested in the fast growing hot months. Even the location of the leaf on the stem can be an indicator of caffeine potential.

Caffeine varies in the fresh green leaf depending on fineness of pluck,” Nigel says. “For any tea, be it black, green or white, the caffeine is highest in the bud. Silver needle (white tea) is 100% bud and has the highest caffeine content.”


I would not rely on the notion that other chemical/compounds in tea will "counteract" the caffeine, without seeing peer reviewed medical research studies. As in, caffeine is a myth in 'counteracting' the effects of alcohol. It may help in stimulating from the depressive effect of alcohol, but as far as reversing the effects of impairment of coordination skills needed to operate motor vehicles...that's another matter all together.

Link to Hicks 1996 study, full pdf d/l available there:

Tea preparation and its influence on methylxanthine concentration
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Re: 30 second decaff trick debunked

Postby ABx » Mar 5th, '10, 22:15

wh&yel-apprentice wrote:I would not rely on the notion that other chemical/compounds in tea will "counteract" the caffeine, without seeing peer reviewed medical research studies. As in, caffeine is a myth in 'counteracting' the effects of alcohol. It may help in stimulating from the depressive effect of alcohol, but as far as reversing the effects of impairment of coordination skills needed to operate motor vehicles...that's another matter all together.

L-Theanine is very well known :) If you take a look around you can find plenty of solid information.

It won't "neutralize" caffeine, but it will counteract the negative effects of the levels of caffeine found in tea. The net result is that you're more alert, but also more relaxed, calm, focused, etc., and you don't get jittery and "wired" or "spun" like you might get otherwise.

^...or you could risk it for better flavor, and estimate amounts of caffeine, and just drink the later infusions, give the 1-3rd infusion to someone else, or dump those on some plants :mrgreen: .

I do know that there are at least some valid reasons for people to cut caffeine out completely. I know someone that takes some medication that prevents your system from metabolizing caffeine, which allows it to build up in the system. Even a single serving of soda can cause major problems for the person for days at a time, so if your doctor is saying that you need to cut caffeine then it might be best to at least discuss the risks :)
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