Tea Antioxidants in Thermos - How Long Do They Keep?

by Greg
(Oregon)

Does tea loose its antioxidants and other benefits if left out for say 8 or 10 hours?

I make tea in the morning and keep it in a thermos.

I'll still drink cups of it in the evening I wondered if it is still high in benefits even after that long.

I read somewhere that Gunpowder tea has the lowest caffeine content. Is there a green tea that has more caffeine than the rest?

Sorry seems like a weird question but even a genius ask questions. Thanks.

Answer:

Greg, tea antioxidants do not tend to keep long. If you brew a high quality tea and keep it in ambient for a few hours, you will notice that the tea liquor turns brown.

This "browning" effects is oxidation.

I suspect when you store you hot tea in thermos, this oxidation effects is somewhat mitigated.

To check if your green tea antioxidants is still intact, pour your tea into a glass and check its colour and taste.

But first, you should test your tea by leaving it in ambient for a few hours.

If you are drinking a quality tea which is high in benefits, you will notice the difference that browning makes to the quality.

Green Tea Caffeine

It may be true that gunpowder green tea contains less caffeine, as they are less likely to be made of tender tea buds, which often contain higher levels of caffeine.

Tea caffeine levels does not correlate with quality. The highest quality green tea often has the highest caffeine level, but its caffeine is being more than offset by the presence of another compound: theanine.

The result is that high quality green tea is more soothing to drink that other so called low caffeine variety.

It may sound radical, but it is true. Check out the story here:

Green Tea Caffeine

Further links along the way will lead you to another article explaining why moderate levels of caffeine is highly beneficial to health.

In fact, tea antioxidants EGCG and caffeine are highly synergistic - they function much more effectively together than separately.

Hope my answer helps.

Comments for
Tea Antioxidants in Thermos - How Long Do They Keep?

Click here to add your own comments

May 20, 2008
The fresher the better
by: Kitty Wang

It is more advisable to drink the tea up shortly after it is brewed as the maximum nutrition would not sustain long.

May 22, 2008
Drink It Hot
by: Julian

Kitty, thank you for the comment. Drinking tea hot is the best option. Especially for very high quality tea.

Compounds like theanine, EGCG and chlorophyll are so vulnerable, leave them exposed to air and they will be gone - just like that.

Leave me wonder what manufacturers do to bottled green tea to preserve what little EGCG they might contain...

Oct 10, 2008
Lasting beneficial qualities of tea
by: steven

Your answer regarding antioxidants in tea seems incorrect. Many company's are extracting the beneficial qualities of tea and selling them in a highly concentrated version which can be added to hot water.

If the anti-oxidants in tea disappear within 6 hours these products would not have any validity.

What is the basis of your information? Just because te tea changes color doesn't necessarily man it loses its potency? Are there any scientific studies on the matter?

Oct 10, 2008
How Long Do Tea Antioxidants Keep?
by: Julian

Steven

You are right to be concerned. I will take the cpportunity to explain myself a bit more.

It is true that tea antioxidants are extremely vulnerable to environmental degradation, for the same reason that these active compounds are so powerful when acting against free radicals in our body.

Processed products such as instant green tea mix or bottled green tea often claim to contain high concentration of catechins/EGCG, but very often when you read into the label (yes, please do it next time!), you'll usually find either some vague wordings or very low level of antioxidants guaranteed.

This doesn't mean that these products won't improve in the future, all it means is that at present, and as far as I am aware, they do not offer the same level of antioxidants as a cup of hot green tea brewed from high quality tea buds (which has been cold stored in sealed pack from the day they are plucked and roasted). Neither are they cost effective.

For further information about scientific studies, please visit

Green Tea Beverage - Best of 7 Types Reviewed

I hope this helps.


Dec 31, 2009
To Cool Or Not To Cool
by: Cindy

Question: would it be beneficial to store tea bags in the refrigerator?

Jan 01, 2010
Tea Bag
by: Julian

When exposed to ambient, it takes only 3 months for tea leaves to acquire enough moisture to oxidize and degrade very rapidly.

How long has the teabag been sitting on the shelf? Personally I believe teabag is only good for black tea, and is of no use for green tea.

If you are talking about green teabag, it probably is not worth the bother because any antioxidants that were there probably have already been lost.

Julian

Nov 30, 2010
"lose" not "loose"
by: Anonymous

lose not loose

Click here to add your own comments

Join in and write your own page! It's easy to do. How?
Simply click here to return to Tea Forum



twitter  Twitter Julian

Amazing Green Tea on Facebook


Amazing Green Tea

The definitive guide to Gourmet Tea and healthy drinks
Tea Alert: 2010 spring green tea season has arrived! Drink same tea as the Chinese White House from 26 cents per cup.
  Home | Share This Site bug Spot a bug? Suggest an improvement and win a prize! Site Map | Privacy Policy | Site Disclaimer