Does boiling water make tea lose antioxidants?

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    Nov 22, 2007 7:18 PM GMT
    Cooking food destroys enzymes, does hot boiling water cause destruction of some of the benefits of tea? Does it destroy herbs antioxidant benefits?

    also

    Do you think there is a big difference in tea bags versus loose leaf tea, besides the taste, is there a vast different in health benefit?
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    Nov 23, 2007 2:40 AM GMT
    According to the tea sommelier I spoke to - yes to the first and no to the second.

    The tea Sommelier program at our community college is very popular and is a two year certification.

    He stressed for green tea the water must be just UNDER boiling point (he gave a specific temperature but I don't recall it and I don't want to steer you wrong. I let it boil then let it cool for 5 minutes before pouring over the tea leaves.

    Some teas I can get only in loose form; others I am content to get in sachets.
    The sommelier did say he liked the triangular bags that Tetley (?) uses but I did not get a chance to ask him more about the shape of the teabag. He did say there was no real difference in taste or procedure for loose or bagged tea.


    The guy I spoke to was emphatic that one must never ever ever use the microwave to heat the water.

    All very interesting. I am a fanatic for herbal teas, but I guess my palate is unsophisticated. I nuke the water to save power.

    I usually pop into my tea shoppe on Fridays so I'll ask.


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    Nov 23, 2007 4:31 AM GMT
    The short answers are "nobody knows" and "no."

    "Anti-oxidant" is just a chemically-illiterate euphemism for "reductant." Molecular oxygen will react with reductants and essentially neutralize them over time. Heat will speed up this reaction, so yes, hot water will cause more of the reductants to oxidize before you can drink them, than would cold water. However it also speeds up the extraction process, so you get more of them in solution than you would otherwise.

    However, if you are comparing boiled water to hot water, then boiled water is actually less oxidizing. The temperature cannot exceed the boiling point, so boiled water is not any hotter than water just before the boil. Boiling is actually a degassing process - boiled water is largely devoid of dissolved oxygen. Therefore, it will not react with reductants in the tea.

    (For example, I boil water to produce solutions of reductants or media for oxygen-intolerant organisms in the lab. Though usually I do it under a blanket of nitrogen.)

    It makes aboslutely no difference whether you heat the water with a microwave, a blowtorch, or a flaming diva. All this nonsense floating around about microwaves is just extraordinarily stupid urban legend.

    Extracting tea with hot (or boiled) water will also neutralize some phytotoxins, so there are benefits as well as costs to cooking.

    But probably there is no measurable difference in any "benefits," which are at best hypothetical in the first place.
  • Salubrious

    Posts: 420

    Nov 23, 2007 4:35 AM GMT
    I agree with you mindgarden, but I do have one question. Can't microwaves superheat water?
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    Nov 23, 2007 4:54 AM GMT
    Can't microwaves superheat water?

    Yes, it sometimes happens, but only slightly. Then, as soon as you disturb the vessel, it boils rapidly and the temperature returns to the normal boiling point. (Unless you shout an expletive and drop it, in which case, it returns to normal floor temperature, and your toe hurts.)

    Of course, you can superheat water significantly by using a closed vessel that allows pressure to build up. In that case, the temperature is controlled by the pressure that you allow. The source of heat makes no difference.

    BTW and completely off-topic. Someone showed me a cool way to reproduce the Miller-Urey primordial soup experiment using only a sealed glass ampule with a small piece of platinum wire inside, and a microwave oven. Very very cool.




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    Nov 23, 2007 4:27 PM GMT
    I can drink loose tea, but the bagged type just tastes like paper. Can't stand it.

    I always learnt 100C for black teas and 95C for green/white teas. If you're making green/white tea, it's also better to remove the water from the heat before it boils instead of boiling it and letting it cool down again, as exessively boiled water can make the tea taste sort of "flat".

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    Nov 23, 2007 7:10 PM GMT
    http://www.thequeensparlour.com/servlet/StoreFront

    ok, so a really good friend is the creator of this store. Her tea is the best!
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    Nov 23, 2007 11:24 PM GMT
    I'm a big time tea drinker. Although tea (especially green tea) has antioxidant, it's like saying eating for the sake of nutrient. I enjoy the it, period. Do so and you'll eventually get the benefit in the long run.

    Typically, the greener the tea, or less the process, the more potent of natural benefit. Another end of tea, such as pu'erh, a very heavy fermented tea, has magical benefit too. I have a friend who has upset stomach all his life, diarrhea twice a week for like 20 yrs. He use to drink light fermented tea, such as Woo long, or Teguanin. Not that it didnt' help, but not as extreme. Then he got involved with Pu'erh tea. and it cured his digestive system. I doubt there's much antioxidant left in a aged pu'erh, but the biochemical balance as the result of aging has other benefit then just antioxidant.

    chinese has always speak highly of tea. so drink up. otherwise just pop pills if you want antioxidant.
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    Nov 24, 2007 12:18 AM GMT
    Well I am not much a tea fan for taste, but I am for the health benefits.
  • atxclimber

    Posts: 480

    Nov 24, 2007 2:40 AM GMT
    Green tea is brewed at about 170-180F for about 2 minutes. Much more time or much higher temperature and it becomes very noticeably bitter. Oolong I believe is the same brewing directions. Probably white, too. Black tea you can brew at 190F and for just about arbitrarily long, it never gets bitter in the same way.

    Being into tea purely for the health benefit is a shame -- it's fantastic! A really good-quality jasmine on a nice brisk spring day, a nice lapsang souchong on a cold rainy winter day... I think tea matches wine in terms of depth, subtlety, and quality. And it doesn't get you drunk, which is handy, say, at work.
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    Nov 24, 2007 3:30 AM GMT
    Re: oolong and jasmine tea

    My experience with cheap tea from small Asian grocery stores is that the cheap jasmine tea is acceptable, but the cheap oolong is really quite bad. If you're going to drink oolong, it's well worth it to spend more for a high-quality tea.
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    Nov 24, 2007 2:38 PM GMT
    lol I don't know if it is a "shame" I am not "into" tea for taste. I am def a tea drinker for health, but I just don't really like the taste of teabags. Wow that sounded bad. Uhm, I do on the flip side like the taste of loose leaf tea it is just more of a pain in the ass to make. Oh and I love ice tea.

    Lately I am trying to drink tea with some soymilk and it seems better. Maybe it is just hot liquid straight up that is not appealing.
  • Alan95823

    Posts: 306

    Nov 24, 2007 3:03 PM GMT
    hippie, if you're enjoying it more when it's watered down with soymilk, there's a chance you may be over steeping your tea. more than 3-4 minutes is definitely too long for most tea I've tried. My favorite black tea (Golden Monkey from mightyleaf.com) has rich notes of caramel and vanilla, but one minute over the steeping time and it's horribly bitter unless you water it down.

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    Nov 24, 2007 5:23 PM GMT
    mindgarden: “The temperature cannot exceed the boiling point, so boiled water is not any hotter than water just before the boil.”

    This doesn’t make any sense to me. If you’re applying heat to the liquid water, then some of its molecules will heat up into steam, which then needs to escape the water. They’ll bounce around in the liquid before escaping, or transferring their kinetic energy to other molecules. While they’re still in the liquid, though, their energy will be where the tea bag is, exposing the tea to water heated beyond the boiling point.

    I love teas, especially green and white, but I’m poor so I can only get the cheap stuff. When I was in college, I didn’t drink nearly as much and I bought high-quality loose leaf teas, but now I drink it by the liter and just get Lipton green tea. =0 It's still good stuff though =)
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    Nov 24, 2007 8:29 PM GMT
    Being chinese, u'd think I grow up drinking tea. but no, I didn't have much knowledge. I always thought tea was kinda mild in flavor, hence the only thing i touched was jasmine tea for the floral quality. then I took a trip to china, and bought some of their top grade jasmine, and My goodness, not all fragrance are created equal.

    another trip to taiwan and met some people who were into tea, and show me some of their woolong collection. My, it's mellow, very fragrant yet not overpowering, and floral despite its' nothing but tea itself with no added flavor. I was amazed at the tea leaf having such dynamic quality due to location and fermentation, it's a shame the demand is so high in eastern world that hardly any good tea is traded to the western world.

    Tea are graded in the quality, what's good are sold loose, ... till the left over, are grounded and pack in teabag. I'd assume tea bag would have all the benefit of loose tea, but for sure the taste itself could be better.
    but if it's dark tea, then the deep flavor make up somewhat.

  • Artesin

    Posts: 482

    Dec 28, 2007 4:50 AM GMT
    If you pour boiling water right over delicate tea, such as green tea, you'll bruise it and cause the flavor to disappear. It might even destroy tannins as if diary was added.