Define Oolong

Owes its flavors to oxidation levels between green & black tea.


Nov 29th, '19, 10:59
Posts: 3
Joined: Apr 24th, '19, 12:42

Define Oolong

by cliffjudith » Nov 29th, '19, 10:59

:?:Can anyone help me please.
Oolong is semi oxidised unlike black tea which is fully oxidised. Why is darjeeling first flush black considered a black tea when it clearly has lots of green unoxidised leaf. Why is this artially oxidised leaf considered black rather than wulong due to partial oxidation.
Secondly, in the manufacture of tie guan yin, the bruised oxidised edges are knocked off and discarded leaving the green unbruised part of the leaf i.e. the unoxidised part. It therefor is still a green tea?
Thirdly, in ball oolongs, the leaves are squashed in a cloth bag or machine compressed to exude juices onto the leaf surface. The tea ball is then broken, dried and the process repeated several times. This leaves flavour chemicals on the leaf surface and these flavours chemically oxidise, whilst those inside the leaf continue, albeit at a reduced rate, enzymatically oxidising.
What the defines an oolong tea?
Be good if someone could please help.

Dec 9th, '19, 11:24
Posts: 3
Joined: Sep 8th, '19, 22:11

Re: Define Oolong

by yiming.chang » Dec 9th, '19, 11:24

cliffjudith wrote: :?:Can anyone help me please.
Oolong is semi oxidised unlike black tea which is fully oxidised. Why is darjeeling first flush black considered a black tea when it clearly has lots of green unoxidised leaf. Why is this artially oxidised leaf considered black rather than wulong due to partial oxidation.
Secondly, in the manufacture of tie guan yin, the bruised oxidised edges are knocked off and discarded leaving the green unbruised part of the leaf i.e. the unoxidised part. It therefor is still a green tea?
Thirdly, in ball oolongs, the leaves are squashed in a cloth bag or machine compressed to exude juices onto the leaf surface. The tea ball is then broken, dried and the process repeated several times. This leaves flavour chemicals on the leaf surface and these flavours chemically oxidise, whilst those inside the leaf continue, albeit at a reduced rate, enzymatically oxidising.
What the defines an oolong tea?
Be good if someone could please help.
Hi,

there are several different ways to distinguish teas. It has to be "Camellia sinensis".

You mentioned and mixed two systems which are used to divide the teas.

First, from china based on how it is processed

Tea is generally divided into categories based on how it is processed.

white, oolong, green, yellow, black. dark are classic standard process for tea. In recently years, there are interesting tea like GABA tea, or Red oolong(hong oolong), that is because these too create the different process then before (and still good to drink).

Second,from japan based on the oxidation

non-oxidation or green tea
semi-oxidation
fully oxidation
post-fermented tea or dark tea

This way need a machine to detect the catechin and calculate percentage decrease.In order to defined the oxidation level.

cool right?

--------------------------------------------------------------
Q: Oolong is semi oxidised unlike black tea which is fully oxidised.

A: Yes, correct in system two and also because different process make them have different oxidation level.

Q: Is darjeeling first flush black considered a black tea when it clearly has lots of green unoxidised leaf?
Why is this artially oxidised leaf considered black rather than wulong due to partial oxidation?

A: Because they are using system 1. based on process.

Q: Secondly, in the manufacture of tie guan yin, the bruised oxidised edges are knocked off and discarded leaving the green unbruised part of the leaf i.e. the unoxidised part. It therefor is still a green tea?

A: Tie guan yin is made in oolong process so base on system 1. it is oolong. Tie guan yin also shows oolong semi oxidation flavor. similar to Taiwan high mountain oolong tea also hardly find brown edges.

Q: Thirdly, in ball oolongs, the leaves are squashed in a cloth bag or machine compressed to exude juices onto the leaf surface. The tea ball is then broken, dried and the process repeated several times. This leaves flavour chemicals on the leaf surface and these flavours chemically oxidise, whilst those inside the leaf continue, albeit at a reduced rate, enzymatically oxidising.

A: There is a fixation stage of tea making, before they squashed or rolled the tea.

Most of the oolong qualities are determined at the moment of fixation(use high temperature to stop the enzy ), the tea maker needs to decide when oxidation level is xe want and stop the oxidation. At least not getting better after rolling.

It continues inside the leaf, if it did not do fixation well.

In order to make tea be brewed, Rolling damaged mesophyll cells and made substance inside tea leaves soluble. Rolling make tea easier to brew.

we can talk more detail about rolling and shaping next time.

So, What the defines an oolong tea?

We can tell for sure, If a Camellia sinensis plant made based on oolong process, it is oolong tea.

Oolong process: solar withering->indoor withering<3-5 times>tossing,shaking -> pile and oxidation, fixation (fry in a hot pot or a drum.) -> rolling (gross oolong tea finished)

Yep, it does not include making a spherical shape or roasting. Only chance to drink gross tea is during process. In fact, experienced pro tea buyer make their deal immediately after trying gross tea.

I am happy you gave examples or it will be not easy to show you the difference.

Thanks!

Yiming

Dec 13th, '19, 04:30
Posts: 151
Joined: Oct 24th, '17, 12:41
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Re: Define Oolong

by 12Tea » Dec 13th, '19, 04:30

cliffjudith wrote: :?:Can anyone help me please.
Oolong is semi oxidised unlike black tea which is fully oxidised. Why is darjeeling first flush black considered a black tea when it clearly has lots of green unoxidised leaf.
I actually noticed this as well. With lots of Indian teas, they tend to blend in some leaves from other types. I've seen black tea and green tea with oolong blended in, most likely to make the taste more smooth. Also, I've seen 'green teas' with a touch of oxidation to smoothen out the flavor, which I would probably regard as a super light oolong. So they obviously do not always fit in the traditional definition of tea types.

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