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ISO3103 Tea Preparation [pdf]

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Re: ISO3103 Tea Preparation [pdf]

#61

Post by isoprophlex »

adrian_b wrote: post #20
bumby wrote: post #13

Earlier quoted context omitted.

What’s the preferred temp for herbal teas?

I prepare my herbal teas in a microwave oven. As an example, I use a glass teapot with 1 liter of water. I preheat the water 4 minutes (@ 1000 W), I add the tea bags, then I heat again for 2 minutes 10 seconds. Obviously the precise times will be different for other microwave ovens and teapots, but the point is that with a microwave oven you can experiment with fine adjustments of the time until you get what you deem…

Smart, reproducible technique! I do hope you are being careful with that: heating liquids past their boiling point can potentially create a superheated state. Very clean containers in a microwave are said to be especially good at causing this.

https://en.wikipedia.org/wiki/Superheating#Occurrence_via_mi...

I've personally never encountered this with water, but have seen it happen with diethyl ether and dichloromethane (at ~40 deg C, so much less scary)

Re: ISO3103 Tea Preparation [pdf]

#62

Post by visarga »

> 5 min at 100 degrees

That would make a bitter cup of green tea. Green tea infuses best at 80 degrees and the time is dependent on the tea.

Green tea taste follows a bell shaped curve, there is a small window of about 10 seconds when the brew is best, you got to stop it precisely at the top. You can use a thermometer and a watch, but the easiest is to just take a sip of the brew every 30 seconds.

Black teas, oolong and puerh can handle 100 degree water and are not as fussy about timing.

Re: ISO3103 Tea Preparation [pdf]

#65

Post by Symbiote »

yaacov wrote: post #5

What’s the purpose of this test? Why would they use boiling water for green tea?

My mum had a job making tea to this standard.

It was part of the quality control at the tea blending / packaging factory. It ensures repeatable consistency. It's not supposed to be the best taste, or follow some tradition or style.

It is the tea equivalent of checking the strength of cement, or measuring the brightness of a light bulb.

Re: ISO3103 Tea Preparation [pdf]

#66

Post by deeg »

flemhans wrote: post #64
codeulike wrote: post #19

George Orwell weighs in on tea-making, 1946 https://www.orwellfoundation.com/the-orwell-foundation/orwel...

I'm surprised he adds milk. Might be a British thing.

I'm a math and tea geek and since it's so very rare when the two worlds overlap I'll take the opportunity to mention it here. The British argument of tea-or-milk-first helped lead to a formalization of random experimentation and the null hypothesis: https://en.wikipedia.org/wiki/Lady_tasting_tea

Re: ISO3103 Tea Preparation [pdf]

#67

Post by satvikpendem »

JasonCEC wrote: post #22

I work with tea both professionally[0] and semi-professionally[1] and will clarify that: - this is for commercial tea, not specialty or "ceremony" grade tea - all of the big commodity houses, blending houses, brand buyers, etc have their own modifications on the standard, and this ISO tea prep standard is most definitely not the "standard" - From elsewhere in the thread: all great tea can be brewed with boiling water…

I made the other comment about not using boiling water. I've also run a tea shop and have imported very high quality tea. I've tried green and white teas with boiling water and they definitely did not taste as good as with 70-80 C water. At boiling temperatures they taste somewhat burnt and astringent.

Re: ISO3103 Tea Preparation [pdf]

#68

Post by kwhitefoot »

isoprophlex wrote: post #61
adrian_b wrote: post #20

Earlier quoted context omitted.

I prepare my herbal teas in a microwave oven. As an example, I use a glass teapot with 1 liter of water. I preheat the water 4 minutes (@ 1000 W), I add the tea bags, then I heat again for 2 minutes 10 seconds. Obviously the precise times will be different for other microwave ovens and teapots, but the point is that with a microwave oven you can experiment with fine adjustments of the time until you get what you deem…

Smart, reproducible technique! I do hope you are being careful with that: heating liquids past their boiling point can potentially create a superheated state. Very clean containers in a microwave are said to be especially good at causing this. https://en.wikipedia.org/wiki/Superheating#Occurrence_via_mi... I've personally never encountered this with water, but have seen it happen with diethyl ether and dichloromethan…

If the starting temperature is 20C then to get to boiling you need to add 80 kelvin * 1000 gram * 4.2 joule/gram = 336 kJ to get to 100C. At 1000 W that takes 336 seconds, or 5 minutes 36 seconds. In practice my 850 W microwave takes nine minutes to raise a litre of milk to 85C from fridge temperature so I don't think there is too much risk of boiling.

Re: ISO3103 Tea Preparation [pdf]

#69

Post by petters »

OJFord wrote: post #28
petters wrote: post #24

Earlier quoted context omitted.

Tea (Camellia sinensis) is not an herb, i.e. not "a plant whose stem does not become woody and persistent (as in a tree or shrub)"

I don't know where you got that definition, but it's obviously not right. It excludes mint and rosemary leaves, for example.

OK, in my native language the translation of "herb" is less used in common language. The definition was from English Wikipedia though
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