Don Mei : Hey teaheads! This is Don from Mei
Leaf. In this video : How Does Brewing Temperature
Affect The Taste Of Tea. In this video we're
going to geek-dive into the intricacies of
tea brewing, and try to figure out how the
experience in the cup is affected by brewing
temperature. If at any point in time you enjoy
this video then make sure you hit it with
a "like", and if you're not following us on
all of our socials then go click those buttons.
Welcome to the first episode in a really extensive
series on Gong Fu brewing. In this series
I want to start from scratch. I want to question
all the rules, and focus in on trying to get
you to be able to brew simply by instinct.
The idea, at the end of all of these lessons,
is that you should be able to look at leaves,
and should be able to get a very good idea,
very quickly, on how to brew. The first episode
is one of the most important - temperature.
Before we move on I'm going to say straight
up [that] we've already done a big chart on
how to brew your teas. I'll put a link in
the description below, so if you don't want
to go through all of the intricacies of how
we figure all this stuff out, and you don't
want to go through this journey with me, check
out that link in the description below, and
you can find out the brewing temperatures
that I recommend. But as we go through this
series I may change that chart, because what
I would like to do is say: Let's start from
square one. Let's reset now. Now that we've
got lots of knowledge about tea amassed over
lots of videos, let's reset, and let's just
go through, factor by factor, so that we can
build that brewing chart up to be something
that is super accurate. And as I [said], what
I would like to do at the end of it is create
a series of lessons so that you don't need
to look at that chart. You can just look at
the leaves and know how to brew it. In today's
episode we're going to focus on temperature.
Temperature is one of the most overlooked
areas for beginners in tea, and that's why
we're starting here. Now whenever I am assessing
a tea, in terms of its quality, I will use
boiling hot water. The reason is because I
want to extract, as quickly as possible, all
of the positive notes of that tea, but also
the negative notes. I want to expose those
negative notes so that I can select tea. But
after I've selected teas - or when we go to
the short-list of teas, then I want to brew
for appreciation; to brew the most flavorful
cup of tea that I can out of those leaves.
And temperature is very key in that. The reason
[is that] tea is simply a solution. You have
a solid particle, the leaf. You have the solvent,
which is water. You mix those together, and
they create an extracted solution. That is
your tea. And temperature affects not just
the rate of extraction; hotter water will
extract quicker. But it also affects which
components in the tea - which chemicals in
the leaves - get extracted. Some chemicals
are very water-soluble, and it doesn't really
matter too much about what the temperature
is of the water. Whereas other chemicals in
tea are very much dependent on the temperature
of water in terms of the concentration of
their extraction. So what we're trying to
do today is to focus on that second point
- not the rate of extraction, which we'll
deal with in future episodes - but which chemical
constituents in the tea leaves are dependent
on hotter water. So in order for me to do
that I've had to try to limit the amount of
variables here. You'll see that, first and
foremost, I've limited the particle size.
You can see [that] I have ground up these
leaves. This is not something that you will
normally see me do. I'm always talking about
the beauty of [loose leaf and whole leaf]
for higher quality tea. But I want to standardize
the process. So we have the same particle
size for all of these teas. I've got Moonlight
White. I've got Imperial Green. I've got Duck
Shit Oolong, and I've got Yunnan Black here.
I could, of course, have added Puerhs, [like]
ripe Puerhs. I could have [had] yellow teas.
But the point of this exercise - the point
of this experiment here - is to create some
basic rules that we can use as our building
blocks for future lessons. I figure that this
spread of teas will do the job, otherwise
I'll be here forever. So we're standardizing
the particle size. We're going standardize
the time of brewing to 30 seconds. We are
going to standardize, obviously - the water
is going to be exactly the same - and what
I'm going to be doing is I'm going to be brewing
the same amounts of each of these teas in
95 degree [Celsius] water- which is 205 [degrees]
Fahrenheit - and 50 degree [Celsius] water,
which is 120 [degrees] Fahrenheit; there or
thereabouts. In other words, I'm trying to
take away all the variables - as much as is
possible - so that was can isolate, simply,
which chemicals in these tea leaves are reliant
on hotter temperature, and how that affects
the experience. Right. Let's get brewing.
Here we are. We just had a manic brewing session,
but I want to be very clear on what we have
done, so if you want you can recreate this.
We've taken 5 grams of the ground leaves.
We've brewed them in glass, using the same
quality of water. We've been brewing at 95
degrees [Celsius] for 30 seconds, and at 50
degrees [Celsius] for 30 seconds. So that's
205 [degrees] Fahrenheit, and 120 [degrees]
Fahrenheit. We started pouring at the 30-second
mark, so it took a little bit longer than
30 seconds, but it would be even because we're
brewing in exactly the same way, [and] pouring
through the same strainer. Here is the Moonlight
White. You can see the hot and the cold. The
hot, the cold... the hot, the cold... the
hot, the cold. So this is the Imperial Green,
this is the Duck Shit Oolong, and this Yunnan
Black. We've standardized it. The hot ones
we've put straight into an ice bath to bring
down the temperature, and the temperature
now [is] all around the same - around 40 degrees
[Celsius]; so warm but not hot. Obviously,
because these were hotter they took longer
to come down to temperature, which is why
we used an ice bath. I didn't want to wait
too long, because that will mean that the
tea is reacting with the air and will change,
and so we're going to get a slight blurring
of the variables a little bit. So we've tried
our best to keep it as standardized as possible
so that the only true variable here is temperature.
Right. Now wé're going to go through the
kind of main areas of tea experience, and
we're going to talk about the chemical constituents,
and whether or not I notice a difference in
the cup. The first thing that we're going
to talk about is viscosity - [that is] how
thick the texture is in the mouth. I'm not
talking about finish. I'm talking about, just
in the mouth, the thickness of the liquid.
Right? Now, the temperature at which you drink
the liquid is very, very important. Cooler
liquids will be more viscous than hot liquids.
Think about honey. When you heat honey up
it becomes more runny. Whenever you heat a
liquid up it becomes less viscous, less thick.
That's why sometimes when you have boiling
hot tea it feels thinner than cold-brewed
tea. That's not necessarily because it is
actually thicker or thinner due to the chemical
constituents in the tea. It's just, maybe,
about the temperature that you're drinking.
That's why we're standardizing it. Let's go
through these and see if we can figure out
a difference in viscosity. [SIPS TEA] These
are obviously very strong teas, but' I'm just
focusing on viscosity. [SIPS TEA] Whoo! [The]
green tea is strong. [The] temperature is
exactly the same, which is great. That's ideal.
[SIPS TEA] Okay. So viscosity could be caused
by lots of different things, [like] obviously
the structure of the water. But in terms of
extraction, I think - I'm not sure, [as] this
is a lot of experimentation [and] a lot of
guesswork, and I've been doing a fair amount
of research but there's still a long way to
go. But I think it's mostly going to be related
to polysaccharides - polysaccharides, and
pectins especially. These are kind of naturally
occuring thickeners in the plant world. So
[with] polysaccharides, the question is: Does
hotter water extract more polysaccharides
than cooler water. From this test I would
say that the viscosity level is very, very
similar between them. [SIPS TEA] They're all
around the same viscosity, nice and thick.
They change according to tea type, definitely.
[SIPS TEA] That's a later episode, when we
talk about the tea types. When we amass all
of the information that we gather we can apply
them to tea types. But let's forget about
that for a second and comparing like-for-like,
the same teas, I notice a very, very small
difference [SIPS TEA] in viscosity. I will
say that, potentially, the hotter one is a
little bit more viscous. Therefore, my conclusion
is that whatever chemicals are contributing
to thickness are not very dependent on temperature.
So you don't have to worry too much about
whether or not you should use cooler or hotter
water to make a thicker textured tea. Moving
on [from] that, let's move straight on to
sweetness, because sweetness [is] also caused
by polysaccharides, for the most part. Again,
from tasting these teas, I don't notice a
major difference in the sweetness. [SIPS TEA]
What I am noticing - and we'll talk about
it a little bit later - is that obviously
the hotter brewed ones are slightly more bitter.
So I'm having to just cancel out that bitterness
in my thought process, or in my analysis,
because obviously, when you have something
that's more bitter that counteracts the sweetness,
and so you feel like it's less sweet. But
if I just focus - and this is the hard part
- on isolating sweetness [SIPS TEA]... hold
on. I think that the cooler one tastes a little
bit sweeter to my taste buds, but I don't
think that that's because more polysaccharides
have been extracted in the cool one. I think
it's simply because there are more bitter
notes in the hotter brewed tea, and therefore
it's kind of fooling my taste buds a little
bit. Because if I isolate just trying to focus
on the sweetness, I think that there's very
little difference between them. So polysaccharides,
which Ithink contribute to thickness, viscosity,
and sweetness in the tea, I think is not too
dependent on the extraction temperature. Let's
move on. We've already spoken about it before.
Let's talk about bitterness and astringency.
Now, bitterness and astringency are different
things, but they usually come together. I've
done a video about astringency. Go check that
out. [It's] very in-depth about the cause
of astringency. But overall, the cause of
bitterness and astringency is generally due
to polyphenols - especially catechins - and
xanthenes, i.e. caffeines. And I can tell
you, without a doubt, from tasting these [SIPS
TEA] that those chemicals compounds are definitely
affected by temperature. So the hotter you
brew the more bitter it's going to be, [and]
the hotter you brew the more astringent the
tea is going to be. Right, let's move on to
savoriness, and savoriness is going to come
from the amino acids in the tea - especially
theanine. Theanine [gives it] that savory,
umami note to the tea. [SIPS TEA] I should
do it with green, because that's the richest
in theanine. [SIPS TEA] It's very salty. It's
got a nice umami flavor, with the hot, [SIPS
TEA] and I would say, again, a very similar
on the cold. So again, just like sweetness,
I think that savoriness is going to be around
the same amount depending on the temperature
that you brew, right? We're going to talk
about time and length of brew in future episodes.
I'm just focusing solely on the extraction
temperatures of these compounds. All right,
let's move on to the structure in the mouth,
and the finish - the length of finish. This
is going to be a bit more difficult. I need
to have some water, just to try to clear the
palate a little bit; to wash off the minerals
that are on my tongue. Because in my research,
and in my opinion, the level of mineral extraction
from the tea leaves is going to play heavily
in terms of the structure, In other words,
the physical sensation of the tea after you've
swallowed, and the length of the finish - how
long the persistent feeling and taste is on
the mouth, throat, and through the nose. So
minerals, I think, are the main factor here
in terms of causing those factors in tea;
those experiences in tea. Let's taste Moonlight
White. [SIPS TEA] The hot has a very dry,
quenching finish. I'm getting a lot of minerality.
I'm getting a length through the nose. I'm
picking up those kind of honeyed notes, [and]
a little bit of fermented flavors, [like]
fermented fruits [such as] fermented apricots
in there, and it stays. It stays. Let's [have]
a little wipe, [SIPS WATER] [to] erase the
minerals a little bit from my tongue. [It's]
relatively neutral, [although] obviously there's
going to be some persistence of minerality.
[SIPS TEA] So I'm not focusing on flavor here.
[It's] softer - much, much softer, and I can
tell you right now that across the board that's
going to be the case. Definitely, in my opinion,
hotter water will bring out more of those
minerals, which means that you're going to
have a more structured finish, you're going
to have a little bit more quench, [and] you're
going to have a bit more length, the hotter
you brew. So hotter means more structure and
longer finish. Whereas if you go cold you're
going to get a very soft finish, and the finish
is going to be much shorter. Finally, let's
talk about flavor - [which is] obviously the
most important on, and the most complicated
one. This is very, very difficult, because
once again, the perception of flavor, first
of all, is very individual. And secondly,
the temperature at which you drink the tea
is going to make a massive, massive difference,
because you're flavor perceptions are dictated
by temperature. It's very important. This
is why drinking out of small cups with Gong
Fu brewing is a desired thing. It brings the
temperature down to a nice, drinkable, warm
temperature rather than scolding hot. Because
when you have hot liquid [the] taste profile
changes quite dramatically. So let's talk
about flavor. Let's go through each of these
teas, one by one, and I'm going to give you
my initial snapshot of the differences in
flavors. [SIPS TEA] Í'm getting bitter - obviously,
we talked about that. But we're talking about
these volatile aromatics now. Forget the bitterness,
forget the catechins, forget the polyphenols.
What we're talking about now is all of the
aromatics - those complex aromatics which
make up a tiny percentage of the dry weight
of the leaf, but contribute to such a large
percentage of the actual experience. On this
one I'm getting woodsy notes. [SIPS TEA] I'm
getting a little bit of cream. I'm getting
some vanilla. I'm getting some of those floral
notes, but more [of] the sweeter end of the
floral notes. Let's taste the cooler-brewed
[one]. [SIPS TEA] [There's] much, much higher
spectrum flavors. I'm talking mountain air
[and] mountain flowers. The flowers that I
was tasting here [have] less of the sweetness
[and] more of the aroma. I'm talking grass-
[like] fresh mowed grass- just when it's starting
to become hay; when it's just starting to
dry, and releasing all of those cut grass
notes as it dries. Let's taste the Imperial
Green. [SIPS TEA] [There's] nuts - lots of
nuts; lots of roast. I'm getting just dark
hazelnuts, [and] chestnuts. There is green,
obviously. I'm getting some grass, but it's
very, very dark. [SIPS TEA] Again, the opposite.
I'm getting nuts, but they taste like raw
nuts. They taste like freshly picked nuts
that you [break] up and you can eat, like
cobnuts [or] things like that - and a lot
of grass. [SIPS TEA] [The] "Duck Shit" [is]
very, very honeyed. [there's] some fruit - more
tropical fruit end [of the] spectrum. [There's]
things like custard apples, [and] things like
a little bit of almond, but baked almonds.
[SIPS TEA] Again, the fruit comes through.
Now I'm getting mangosteens. I'm getting those
light, white fruits [like] lychees. [SIPS
TEA] Almonds as well. That's baked, [and]
this one's not. This one is more like [raw]
marzipan. [The] Yunnan Black [SIPS TEA] [has]
malt, dark chocolate, [and] a little bit of
winey note to it. [SIPS TEA] [It's] much more
floral - so much more floral. I'm getting
some rose, lilacs, [SIPS TEA] and a bit more
herbaceous as well. [There's] little bits
of mountain flowers [and] mountain herbs.
[There's] a little bit of wintergreen in there.
So the overall takeaway with this is [that]
even when you drink the tea at the same temperature
- so we're not being influenced by the temperature
of the actual drinking liquid - when you brew
hotter you are going to extract more of those
base notes, [and] you are going to extract
more of those low notes. Whereas when you
brew cooler you're going to extract more of
the high notes. [Is] it the extraction, or
is it that the high note volatiles are very,
very sensitive [and] very, very fragile, and
so therefore when you hit it with hot water
they dissipate quicker, whereas when you brew
it in cooler water they hold. They stay in
the cup for longer. Now, this is the next
stage of this. We need to take all of this
information and move it on to the next stage.
I want you to experience this yourself. So
what I'm going to do is in the next video
I'm going to introduce you to a particular
way of brewing that I think works for certain
types of tea. In order for you to do that
experiment with me you're going to need the
same tea as me, ideally. So what we're going
to do is, if you're watching this when this
is released - which is [in the middle] of
August, 2018 - we're going to put one tea
- it's called "Sip Spring" - we're going to
put that tea - the pouch of it; because you're
going to need a fair amount to do these experiments.
We're going make a pouch of it online, and
it's going to be on sale so that you can pick
one up. We're going to be doing the next stage
of this - the next lesson in this Gong Fu
Master series - we're going to be doing it
in about three weeks time. So that gives you
enough time to pick this up - pick up this
Sip Spring - and then we can do this experiment
together. The next stage of this experiment
is all about how we can use temperature to
control the aromatics so that you get the
best of both worlds - both the low end, and
the high end, and the structure. So let's
recap. I know I'm giving you a lot of information,
and I know it can feel like it's a bit overwhelming
and a bit confusing, and I'm sorry, but I'm
just trying to break it up into bite-sized
pieces, and I promise [that] by the end of
this series you will be a Gong Fu brewing
master. I promise you that. Okay, so take-away
points. We're not talking about extraction
rate. That's a separate discussion. When you
control all of the variables - when you standardize
all the variables and you just focus on which
chemicals in the tea leaves are affected heavily
by the brewing temperature - we can say the
following: the first is that, in terms of
sweetness and savoriness, which comes, in
my opinion, from polysaccharides and from
amino acids in the leaf, I don't think there
is a major difference in the extraction concentration
at higher or lower temperatures. Obviously,
if you brew it in ice water it's always going
to extract slower. But generally, it's not
a big deal. Similarly, viscosity - which is
related to polysaccharides and pectins, in
my opinion, is not heavily affected by temperature.
What is affected by temperature is the following:
bitterness. Hotter water is definitely going
to make for more bitter tea. Astringency,
hotter water is definitely going to make for
more astringent tea. Structure, hotter water
is going to give you more minerality, which
means you're going to have a more structure
finish, rather than a soft finish. Length,
the length and persistence of the physical
sensation, and the flavor and aromas, persist
longer with hotter water. Then in terms of
flavors and aromatics, we're going to move
that onto the next video, but [the] general
rule is cooler brewing will preserve more
of those top notes, whereas hotter water is
going to shift the EQ of the flavor much more
towards the basier, more woodsy, notes of
the tea. I hope that that takeaway is enough
to keep you watching for the next one. I promise
you [that] we're going to roll through all
of these master lessons, and by the end of
it you're going to be able to look at leaves
and know how to brew them. That's it teaheads.
If you've made it to the end of this video
then make sure you hit it with a "like". Follow
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out on any news and videos from Mei Leaf HQ.
If you're ever in London then come visit us
in Camden to say "Hi!" and taste our wares.
If you have any questions, comments, or video
ideas then please fire them over. Other than
that, I'm Don from Mei Leaf. Thank you for
being a part of the revelation of true tea.
Stay away from those tea bags, keep drinking
the good stuff, and spread the word, because
nobody deserves bad tea. Bye [WAVING]
