Funadvice Logo
Explore Join
More Food & Dining Questions

Why does my green tea become brown after being in my thermos for an hour or two?

My thermos is not rusting or rusted. It only happens when i put green tea in it.

Become an Expert →
Answer #1

This, of course is based on my own knowledge..or possibly not!

The problem is the constant high temperature at which the tea is kept in a thermos. For instance, a cup of brewed tea left standing won’t lose too much “greenness,” even overnight. A teapot full of tea, however, will take on a slightly brownish hue. That’s because the pot holds the heat in longer than a cup. A thermos, obviously, retains heat much, much better.

Tea that turns too brown has lost much of its antioxidant content. That’s why green tea is healthier than oolong or black (English) teas, which are brown because the leaves were dried in the sun after harvesting and then allowed to ferment. Sun-drying allows an enzyme in green tea (called polyphenol oxidase) to oxidize (i.e., combine with oxygen in the air). The oxidized enzyme alters the disease-fighting catechins, which give the tea its green color. Fermentation also causes the catechins to be oxidized. Oxidized catechins give black tea its distinctive aroma and flavor but don’t have the health benefits of catechins in their natural state.

Consequently, when green tea is harvested, the grower’s first concern is to get the leaves to the steaming or frying vat as quickly as possible. This stops oxidation and fermentation, locking in green tea’s distinctive earthy flavor and aroma – and preserving the catechins.

But green tea’s catechins also begin to break down after brewing. (And sustained high temperatures, as in a thermos, only accelerate this process.) This is why I always recommend that people drink their green tea within an hour of brewing.

(And think of how long bottled, ready-to-drink green tea has been sitting around! Without artificial green coloring, it wouldn’t be green at all.)

Answer #2

._. well.

Answer #3

Hi buddy :

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

in order to thank everyone, characteristic, novel style, varieties, low price and good quality, and the low sale price. Thank everyone

I suggest: : novel Jordan FLIGHT 23 RST LOW-1 Price:$ 48USD

==== ( http://funadvice.com/r/bu3uht8b8a5/views.asp?hw_id=1947&class_id=4&sort_id=10&nsort_id=81 ) =====

$33 True Religion jeans, Ed Hardy jeans,LV,Coogi jeans,Affliction jeans

$30 Air Jordan shoes,Shox shoes,Gucci,LV shoes

50%Discount winter fashion :Sandle,t-shirt,caps,jerseys,handbag and brand watches!!!

$15 Ed Hardy ,LV ,Gucci Bikini

$15 Polo, Ed Hardy, Gucci, LV, Lacoste T-shirts

$25 Coach,Gucci,LV,Prada,Juicy,Chanel handbag,

$10 Gucci,Ed Hardy sunglasses

$9 New Era caps.

give you the unexpected harvest

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8bnr9 ) =====

Answer #4

Hi buddy :

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

in order to thank everyone, characteristic, novel style, varieties, low price and good quality, and the low sale price. Thank everyone

$33 True Religion jeans, Ed Hardy jeans,LV,Coogi jeans,Affliction jeans

$30 Air Jordan shoes,Shox shoes,Gucci,LV shoes

50%Discount winter fashion :Sandle,t-shirt,caps,jerseys,handbag and brand watches!!!

$15 Ed Hardy ,LV ,Gucci Bikini

$15 Polo, Ed Hardy, Gucci, LV, Lacoste T-shirts

$25 Coach,Gucci,LV,Prada,Juicy,Chanel handbag,

$10 Gucci,Ed Hardy sunglasses

$9 New Era caps.

give you the unexpected harvest

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8bnr9 ) =====

Today for you recommend products :

—- shoes for male Name:Kobe IV Olympic-1 $ 53USD ——

==== ( http://funadvice.com/r/bu3uht8b8a5/views.asp?hw_id=964&class_id=1&sort_id=6&nsort_id=49 ) =====

Answer #5

Hi buddy :

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

in order to thank everyone, characteristic, novel style, varieties, low price and good quality, and the low sale price. Thank everyone

$33 True Religion jeans, Ed Hardy jeans,LV,Coogi jeans,Affliction jeans

$30 Air Jordan shoes,Shox shoes,Gucci,LV shoes

50%Discount winter fashion :Sandle,t-shirt,caps,jerseys,handbag and brand watches!!!

$15 Ed Hardy ,LV ,Gucci Bikini

$15 Polo, Ed Hardy, Gucci, LV, Lacoste T-shirts

$25 Coach,Gucci,LV,Prada,Juicy,Chanel handbag,

$10 Gucci,Ed Hardy sunglasses

$9 New Era caps.

give you the unexpected harvest

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8b8a5 ) =====

==== ( http://funadvice.com/r/bu3uht8bnr9 ) =====

More Like This
Ask an advisor one-on-one!
Advisor

Montauk Tea

Food & Beverages, Health & Wellness, Local Business

Advisor

Narendra Tea Company

Tea Manufacturers, Tea Exporters, Tea Suppliers

Advisor

Wild Tea Qi Official Website

茶叶, 采样品, 茶叶礼盒

Advisor

Tastings Tea

Organic Tea, Specialty Tea, Imported Tea

Advisor

Blackish Tea

Food & Beverage, Lifestyle, Personal Blog