PDA

View Full Version : Homemade decaffeinated tea


nimzov
15th December 2009, 11:49 AM
I decaffeinated my tea by pourring a small amount of hot water then I wait 20 seconds and throw away this water which is supposed to contain much of the caffeine dissolved. This liquid is brownish for regular tea.

That is fine for regular tea. But when I do the same procedure with green tea, the liquid is colorless.

My question are : 1- Is caffeine brown or colorless when dissolved in water.

2- Does my procedure extract the same amount of caffeine with green tea as it does with regular tea ?

Thanks.

JoeTheJuggler
15th December 2009, 04:43 PM
I use that method for brown tea, but I haven't done so for green tea. How does it taste?

To me, that matters more than the color anyway. Could it be that you need to use proportionately more tea?

Also I seem to recall that green tea should be brewed with a slightly lower water temp. Maybe that's a factor?

ETA: I just found this, but I have no idea how authoritative a source it is:

Green tea, unless it is decaffeinated, also contains caffeine. Normal green tea itself may contain more caffeine than coffee, but the length of infusion with hot water, and the number of time you use the green tea leaves can greatly reduce your caffeine intake. Experiments have shown that tea after a first 5 minute brew contains 32 mg caffeine. But if the same leaves are then used for a second and then a third five minute brew, the caffeine drops to 12 mg and then 4 mg.
Linky (http://www.medicinalfoodnews.com/vol10/2006/green_tea).

ponderingturtle
15th December 2009, 04:47 PM
I use that method for brown tea, but I haven't done so for green tea. How does it taste?

To me, that matters more than the color anyway. Could it be that you need to use proportionately more tea?

Also I seem to recall that green tea should be brewed with a slightly lower water temp. Maybe that's a factor?

ETA: I just found this, but I have no idea how authoritative a source it is:


Linky (http://www.medicinalfoodnews.com/vol10/2006/green_tea).
They are also missing that you generally use a lot more coffee beans than tea leaves to make coffee. I didn't quite understand this the first time I made coffee for my girlfriend. She claims she thought it was sweet of me, but rather ineffectual coffee.

Madalch
15th December 2009, 04:56 PM
I decaffeinated my tea by pourring a small amount of hot water then I wait 20 seconds and throw away this water which is supposed to contain much of the caffeine dissolved. This liquid is brownish for regular tea.

That is fine for regular tea. But when I do the same procedure with green tea, the liquid is colorless.

My question are : 1- Is caffeine brown or colorless when dissolved in water.

2- Does my procedure extract the same amount of caffeine with green tea as it does with regular tea ?

Thanks.

I don't know how quickly the caffeine dissolves in hot water as compared to the flavourful components of tea, but I doubt you're getting it all out.

But caffeine is colourless in solution.

Fat Bottom Gurl
15th December 2009, 05:01 PM
I don't know if this is a stupid question, but why not just purchase decaffeinated tea? Is there something wrong with decaf tea - I buy it.

nimzov
15th December 2009, 05:06 PM
I use that method for brown tea, but I haven't done so for green tea. How does it taste?

To me, that matters more than the color anyway. Could it be that you need to use proportionately more tea?

Also I seem to recall that green tea should be brewed with a slightly lower water temp. Maybe that's a factor?

ETA: I just found this, but I have no idea how authoritative a source it is:

Linky (http://www.medicinalfoodnews.com/vol10/2006/green_tea).
I see no difference before and after decaffeination, but I am no reference for taste. ;)

I know that caffein is very soluble in hot water and that is the explanation for this decaffeination process. But I don't understand why the liquid resulting from decaffeination of green tea is colorless while it is brown for regular tea. Unless the brown color is not from the caffein.

Thanks for the link.

ETA: Ok Madalch just answered that caffein is colorless in solution.

nimzo

nimzov
15th December 2009, 05:14 PM
I don't know if this is a stupid question, but why not just purchase decaffeinated tea? Is there something wrong with decaf tea - I buy it.
There are some process to decaffeinate tea that use chemicals like methylene chloride and ethyl acetate. Another process uses water.

I do it myself because it is easier for me to find non-decaf tea and I am not sure I want to drink tea that was decaffeinated with those chemicals. (ETA: ethyl acetate is apparently found in wine, so it is not toxic)

http://recipes.howstuffworks.com/question480.htm

nimzo

casebro
15th December 2009, 05:28 PM
So why bother drinking tea after you wash all the flavor out along with the caffeine? Why not just have a cup of hot water?

Oh, I understand, you want homeopathic tea? That would be a 2I dilution? ;)

I guess you could have a glass of wine if you don't want caffeine. Or milk, Or Orange juice, or....

Or cut the caffeine in half by buying loose tea and using 1/2 half the usual amount? Or use one tea bag all day? First cup is high test to get your morning started, later cups are decaf. Evening cup will not keep you awake. Start full blast in the morning again.

shandyjan
15th December 2009, 05:44 PM
I buy decaffinated teabags to drink at night, when I remember. I need the caffeine in the daytime, but need the flavour at night. Taking the caffeine out by rinsing with hot water would mean brewing longer, and I dont like the stewed taste!

nimzov
15th December 2009, 05:46 PM
So why bother drinking tea after you wash all the flavor out along with the caffeine?I don't think the process washes all the flavor out.

The caffein is much more soluble in hot water than the other components of tea. So I don't think this process alters the taste that much. But your mileage may vary. ;)

nimzo

Madalch
15th December 2009, 06:00 PM
There are some process to decaffeinate tea that use chemicals like methylene chloride and ethyl acetate. Another process uses water.

I do it myself because it is easier for me to find non-decaf tea and I am not sure I want to drink tea that was decaffeinated with those chemicals. (ETA: ethyl acetate is apparently found in wine, so it is not toxic)

You can rest assured that there is no dichloromethane left in the decaffeinated tea- it has a low boiling point, and I'm sure it wouldn't be legal to sell tea that contained detectable quantities of dichloromethane in it.

Another popular method of decaffeinating coffe (at least- not sure if it's used for tea) is supercritical carbon dioxide. CO2 at a pressure and temperature where it's neither a liquid nor a gas is an excellent solvent for caffeine, and doesn't extract any of the flavenoids in the tea. Then they lower the pressure to turn the CO2 into a gas, and the caffeine turns into snowflakes and settles to the bottom of the tank. Supercriticalcool.

tesscaline
15th December 2009, 06:03 PM
If you are really all that concerned about the caffeine, why are you not drinking herbal teas instead?

No decaffeination process will remove 100% of the caffeine, but it will remove the flavor of the tea, especially with lighter flavored teas like green teas.

nimzov
15th December 2009, 06:58 PM
If you are really all that concerned about the caffeine, why are you not drinking herbal teas instead?
I also drink herbal tea.

I am concern with caffeine, because caffeine give me bladder problem, which I do not have, with decaffeinated tea.

Some commercial tea are decaffeinated to 0.2%.

tesscaline
16th December 2009, 04:08 AM
I also drink herbal tea.

I am concern with caffeine, because caffeine give me bladder problem, which I do not have, with decaffeinated tea.

Some commercial tea are decaffeinated to 0.2%.Caffeine is a natural diuretic... So, yeah, it can cause bladder issues. If it's that big of a problem for you, why not just eliminate the teas that would have any caffeine in them at all, from your diet? Then you wouldn't have to worry about it at all.

It just seems to me that you're taking an overly complex approach to something that should be a relatively simple...

ponderingturtle
16th December 2009, 05:01 AM
There are some process to decaffeinate tea that use chemicals like methylene chloride and ethyl acetate. Another process uses water.

I do it myself because it is easier for me to find non-decaf tea and I am not sure I want to drink tea that was decaffeinated with those chemicals. (ETA: ethyl acetate is apparently found in wine, so it is not toxic)


There is a flaw in your logic about toxicity here.

Pup
16th December 2009, 05:46 AM
Originally Posted by nimzov http://forums.randi.org/helloworld2/buttons/viewpost.gif (http://forums.randi.org/showthread.php?p=5417483#post5417483)
(ETA: ethyl acetate is apparently found in wine, so it is not toxic) There is a flaw in your logic about toxicity here.


LOL. I was thinking the same thing.

Cuddles
16th December 2009, 06:04 AM
I decaffeinated my tea by pourring a small amount of hot water then I wait 20 seconds and throw away this water which is supposed to contain much of the caffeine dissolved. This liquid is brownish for regular tea.

Is there any evidence that this actually removes a significant amount of caffeine? No matter how soluble caffeine is, it's not a matter of simply dissolving it, it needs to be leached out of the leaves. Does that actually happen any faster for caffeine than the rest of the tea? Or did someone just see the relative solubilities and assume that it must be the case?

casebro
16th December 2009, 06:26 AM
Caffeine is a natural diuretic... So, yeah, it can cause bladder issues. ...


Two things: Latest studies claim coffee is not a diuretic. Drink a pint of coffee, urinate a pint. It's just the excess water that makes you think you are diureticising.

Plus, isn't additional urine flow usually a good thing for bladders, kidneys, and related plumbing ?

nimzov
16th December 2009, 07:21 AM
(ETA: ethyl acetate is apparently found in wine, so it is not toxic)
There is a flaw in your logic about toxicity here.

Is wine toxic ? I don't know I do not drink wine. :p

nimzo

nimzov
16th December 2009, 07:56 AM
Is there any evidence that this actually removes a significant amount of caffeine? No matter how soluble caffeine is, it's not a matter of simply dissolving it, it needs to be leached out of the leaves. Does that actually happen any faster for caffeine than the rest of the tea? Or did someone just see the relative solubilities and assume that it must be the case?

---


Decaffeination of fresh green tea leaf (Camellia sinensis) by hot water treatment.

Huiling Lianga, Yuerong Liang, Junjie Donga, Jianliang Lua, Hairong Xua and Hui Wanga

Tea Research Institute, Zhejiang University, 268 Kaixuan Road, Hangzhou 310029, PR China

When fresh tea leaf was decaffeinated with a ratio of tea leaf to water of 1:20 (w/v) at 100 °C for 3 min, caffeine concentration was decreased from 23.7 to 4.0 mg g−1, while total tea catechins decreased from 134.5 to 127.6 mg g−1; 83% of caffeine was removed and 95% of total catechins was retained in the decaffeinated leaf. It is considered that the hot water treatment is a safe and inexpensive method for decaffeinating green tea..
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6R-4JRT34R-4&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1138274321&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=46846ccffded0fbab0735f571471686d

Unfortunately, I do not have access to the full article for the details.

tesscaline
16th December 2009, 03:06 PM
Two things: Latest studies claim coffee is not a diuretic. Drink a pint of coffee, urinate a pint. It's just the excess water that makes you think you are diureticising.

Plus, isn't additional urine flow usually a good thing for bladders, kidneys, and related plumbing ?
1) I never claimed coffee was a diuretic. I said caffeine was.
2) Can you link to these "recent studies"? I am aware of the ones showing that caffeine does not cause dehydration, but that's not the same as caffeine not having any diuretic effect at all.

http://www.mckinley.illinois.edu/Handouts/caffeine.html
Its diuretic effects are usually compensated for by the beverage's fluid content.
http://www.nytimes.com/2008/03/04/health/nutrition/04real.html
Most studies have found that in moderate amounts, caffeine has only mild diuretic effects
http://advance.uconn.edu/2002/020722/02072207.htm
While there have been several studies done that show caffeine is a mild diuretic, there is no evidence that exercise, when combined with the consumption of caffeine or caffeinated beverages, will result in chronic dehydrationandCaffeine consumption causes a mild diuresis very similar to that of water (water, when consumed in large volume, increases urine output)

quarky
16th December 2009, 04:25 PM
Home extraction (and purification) of caffeine is a laudable venture.
Historically, we drink infusions of plant biomass that contain caffeine for the caffeine.

But I can see the point of extracting it, as long as it's because you want to save it for an emergency, or you want to gift a caffeine junkie with a gram of the clean product.

Flushing it down the drain is an insult to the plant that contains this legal stimulant.

JoeTheJuggler
16th December 2009, 04:38 PM
So why bother drinking tea after you wash all the flavor out along with the caffeine? Why not just have a cup of hot water?

Oh, I understand, you want homeopathic tea? That would be a 2I dilution? ;)

Nah--it's nothing like homeopathy.

As mentioned, you can remove a substantial amount of the caffeine in a first brief infusion without losing the tea flavor.


There are some process to decaffeinate tea that use chemicals like methylene chloride and ethyl acetate. Another process uses water.

I do it myself because it is easier for me to find non-decaf tea and I am not sure I want to drink tea that was decaffeinated with those chemicals.
My motive is that decaf teabags cost around 400% what regular generic bags cost. (And the generic bags don't come individually wrapped--IMO extraneous packaging.)

I also brew a lot of loose leaf tea, and I don't think that's available as decaf at all. (It might be, but I'd be willing to bet it's still a lot pricier than regular.)

And I drink a LOT of tea. My aim is for about half-caf. (If I don't use this method, I would use half decaf bags and half regular.)

ponderingturtle
16th December 2009, 04:38 PM
Two things: Latest studies claim coffee is not a diuretic. Drink a pint of coffee, urinate a pint. It's just the excess water that makes you think you are diureticising.

Plus, isn't additional urine flow usually a good thing for bladders, kidneys, and related plumbing ?

I thought caffeine was a diuretic, it was just not that strong so coffee will hydrate you, if not as effectively as water.

JoeTheJuggler
16th December 2009, 04:40 PM
Is wine toxic ?

Well. . you can certainly get intoxicated drinking wine.

ponderingturtle
16th December 2009, 04:40 PM
Is wine toxic ? I don't know I do not drink wine. :p

nimzo

Wine contains many compounds that are toxic. If something is toxic or not all depends on the dosage.

Drinking it by quart is probably a very bad idea. Drinking it in the levels in wine is probably not that bad.

nimzov
16th December 2009, 05:41 PM
My motive is that decaf teabags cost around 400% what regular generic bags cost. (And the generic bags don't come individually wrapped--IMO extraneous packaging.)

I also brew a lot of loose leaf tea, and I don't think that's available as decaf at all. (It might be, but I'd be willing to bet it's still a lot pricier than regular.)

And I drink a LOT of tea. My aim is for about half-caf. (If I don't use this method, I would use half decaf bags and half regular.)
Yes and it is inexpensive and a very easy operation that takes 20-30 seconds.

Taffer
16th December 2009, 10:14 PM
Tea without caffeine? I don't understand the point, but...

Green tea, unless it is decaffeinated, also contains caffeine. Normal green tea itself may contain more caffeine than coffee, but the length of infusion with hot water, and the number of time you use the green tea leaves can greatly reduce your caffeine intake. Experiments have shown that tea after a first 5 minute brew contains 32 mg caffeine. But if the same leaves are then used for a second and then a third five minute brew, the caffeine drops to 12 mg and then 4 mg.

5 minutes? That's far too long a brew for green tea. Try 30s to 1 minute.

tesscaline
17th December 2009, 01:35 AM
Tea without caffeine? I don't understand the point, but...



5 minutes? That's far too long a brew for green tea. Try 30s to 1 minute.Indeed. 2 minutes max for best flavor. Anything more than that ruins the tea.

Cuddles
17th December 2009, 08:17 AM
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6R-4JRT34R-4&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1138274321&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=46846ccffded0fbab0735f571471686d

Unfortunately, I do not have access to the full article for the details.

Thanks. I notice that the abstract specifically says that this works for fresh tea leaves, but that for dry ones, such as would be found in teabags, a large amount of the flavour and other stuff is also lost. Do you, and any others who have said they use this technique, only use it for fresh leaves? JoeTheJuggler, for instance, specifically mentions using teabags, so it would appear that at least in his case there would be no benefit from doing this.

nimzov
17th December 2009, 08:37 AM
For tea bags as compare to fresh leaves, I guess that the percentage of caffeine and catechins removed could be different, but I am not sure that means that there is no benefit.

JoeTheJuggler
17th December 2009, 08:38 AM
Thanks. I notice that the abstract specifically says that this works for fresh tea leaves, but that for dry ones, such as would be found in teabags, a large amount of the flavour and other stuff is also lost. Do you, and any others who have said they use this technique, only use it for fresh leaves? JoeTheJuggler, for instance, specifically mentions using teabags, so it would appear that at least in his case there would be no benefit from doing this.

ETA: Also, the statement you're referring to in the abstract was talking about a 3 minute infusion. I would never leave it for that long and then throw it out.

With black tea, I've used it for both fresh leaves and teabags, and I would agree that you get better results with fresh leaves.

However, since I go for about a half-caf final result, when I use bags, I do the first infusion with several bags (removing something like 80% of the caffeine if the interwebs are to be believed), then add a couple more un-diluted bags for the final infusion. But even so, you don't remove all the flavor with that first, brief infusion.

The claim that this technique is akin to homeopathy is wrong.