Comparing Korean Green Tea Grades – A Five-way Tasting


How much do you know about Korean green teas? Considering the volume of green teas produced in China and Japan compared to that produced in Korea, it’s no surprise that Korean green teas are uncommon abroad. Luckily, it’s possible to find these teas online from various producers and in various grades.

I’ll be blind tasting five green teas simultaneously (four from Teas Unique, and one that was purchased for me in Korea) from the Boseong growing area in Korea. The purpose of this tasting is to learn to differentiate between the grades of teas with all else (parameters, terroir) being about the same.

I’ve designed this page so that you can follow along step-by-step with my tasting notes (represented graphically) and make your own conclusions about which tea is which. Certainly nothing beats trying and tasting for yourself, but I’d like to think this is the next best thing!

About Korean Green Tea

When buying Korean green tea, you may encounter some new vocabulary. (At least I did since I don’t speak Korean.) From perusing various western-facing vendors online, it’s clear that if Korean green tea is offered, it’s usually offered by flush. The four most commonly offered flushes are:

First flush: Ujeon (우전)

Second flush: Sejak (세작)

Third flush: Joonjak (중작)

Fourth flush: Daejak (대작)

(The romanization varies; sometimes ujeon is spelled as “woojeon,” joonjak looks like “jung-jak,” etc.) Unlike the flushes of Indian teas like Darjeeling (where each flush roughly corresponds to a different season), the flushes of Korean tea seem to equate more to grades of tea based on the size of the pick.

While it may have been the case traditionally that the Korean green tea flushes were delineated by date (see the Wikipedia article on Korean green tea for the specifics dates), that doesn’t seem to necessarily hold true now. Take, for example, the daejak from Teas Unique (one of the teas I’ll be tasting here). According to Wikipedia, daejak “is made of leaves plucked in late May and after.” Yet the Teas Unique daejak is made from larger leaves picked in April that are sorted out from the other three flushes (this is stated clearly on the product page). That sounds more like a grade than a flush to me.

Does the difference between grade and flush matter that much? Probably not. It’s probably enough just to keep in mind that when it comes to natural products, the only constant is variation. Coming from a world where everything is standardized and packed in plastic, it can be easy to forget that the rhythms of nature – the rains and thaws and storms – determine the harvest, not a calendar.

That said, let’s drink some tea and see what these grades/flushes mean in practice!

The Setup

The question I always find myself asking when I see grades of the same tea for wildly varying prices is: Do the quality differences justify the price? On the Teas Unique page for Boseong tea, you can see that the sejak, joonjak, and daejak are close in price. But the price of the ujeon is dramatically higher than that of the sejak, and is more than twice the cost of the daejak. 

So, what are the difference between these teas, if any, and do these differences justify the increasing cost?

To answer this question, I am trying each of these teas prepared in the same way in a blind tasting. I have tried each of these teas once before on their own and have created review pages here: ujeon, sejak, joonjak, daejak. This adds an extra edge for me to see if my tasting notes for each tea will be similar, now that I’m trying them again in a blind tasting setting.

Lastly, I’m adding in one extra Boseong green tea from a different, unknown company just to make things extra difficult. I received this gift from a family member living in Korea. From their translation, this tea is organic and a third pick.

Meet the Teas

Before conducting the blind tasting, I took some time to get to know the dry leaves. It was my hope that they could give me some hints about how to tell them apart during the actual tasting.

Color-wise, all teas are about the same. Dark, slightly grey-ish green.

Organic 3rd pick:

In size, seems to fit closer to the Teas Unique daejak than the joonjak, but with a less standardized pick. Fresh round sweet hay scent. Squash vegetal scent. More vegetal and less sweet scented than the others in general.


Beautiful elegant soft sweet scent. More refined sweet than vegetal sweet. Leaves are incredibly thin and small. Most are slightly curled.


As with the ujeon, more of a refined scent, but a hint more vegetal. Mix of leaves about the same size as Ujeon and some the same size as the joonjak.


Getting more of a sweet grains scent here than in the others. Greenness that reminds me of matcha in a way. Leaves are larger and more uneven – some seem slightly balled, some curled.


Earthier scent. Deeper notes, but still sweet. Sweet grains, sweet corn. Leaves are perhaps more uniform than the sejak, but all larger and slightly curled.

The Test

I’ve designed this page so that you can follow along with the tasting using pictures and graphics to represent aspects of each tea. Some graphics have extra information in a drop down box underneath. You’ll have to trust my judgement when it comes to relaying this information correctly. But even with that caveat, I hope there’s enough information that you can form your own opinion.

The parameters for this tasting were:

– 2.5g of each tea in an identical 100ml porcelain tasting set. The tasting sets were marked on the bottom with the grade of the tea, and the tea was placed into the corresponding set. These sets were blindly mixed and filled with water, and then marked with a letter on top. The tea liquor was poured out into a cup marked with the same letter.

– each tea steeped for two mins with 98C reverse osmosis water with pink rock salt added (TDS of 50 ppm)

The objective is to match each tea (the Teas Unique Boseong ujeon, sejak, joonjak, and daejak, plus the mystery 3rd pick Boseong tea) to its corresponding letter (A, B, C, D, or E). My guesses and the actual answers are in a couple of drop down boxes near the bottom of this page. No early peeking 😉




Light greenish color like E. Lightly vegetal, but mostly just a faint sweetness.



Very grain-like scent. Hints of marine aromas. Darkish yellow color like D.



Yellow green, less yellow than B and D. Very light hints of a cereal sweetness.



Yellowish color closest to B. Hints of a marine crustacean scent. Grass notes in the background.



Lighter, greener than all others except maybe A. Light cereal sweetness.



flowery grain marine aroma

Very light. Sweet. A hint of flowers later on with a touch of a grain sweetness. This one is noticeably different from the others. Floral aromas fade as it cools and gains some marine aromas.


marine grain aroma

Light marine notes fade quickly to strong grain aroma. Sweet up front which changes to a touch of bitterness, but leaves grain sweetness.


grain grassy aroma

Some grain taste and a bit of grassiness. Very little bitterness and no marine aromas.


marine grain aroma

Very noticeable marine aromas. Some sweet grain aromas. Very strong with a bit more bitterness than the others.


grain vegetal aroma

Heavier than A, but lighter than the others. Much more grain aroma. Sweet, with noticeable vegetal notes but no bitterness.




Refined sweetness, like white sugar instead of vegetal sweetness.


bitter sweet flavors

Bitterness, then an aftertaste of sweetness.



Grain sweetness.


bitter sweet flavors

Bitter with a very slight hint of sweetness later on. Very aggressive flavor change to strongly bitter as it cools.



A lighter sweetness. Not quite a grain sweetness like C; more of a refined sweetness like A.



soft oily watery texture

Soft, oily, watery.


velvet texture

Hint of astringency. Velvet texture.


soft oily texture

Soft and oily like A.


suede dry cooling texture

Suede, dry, cooling. Becomes more astringent as it cools.


oily watery texture

Oily, watery.



medium light body


medium body


medium body


medium body


medium light body



Aroma and flavor. Refined sweetness with florals early on. Zero astringency.


Flavor stronger than aroma and texture. Flavor gets more bitter over time, and texture feels a little more astringent as well.


Tilts equally towards flavor and aroma. Sweetness without bitterness.


Strongly flavorful, some texture, some aroma. Much stronger even than B (which is noticeably stronger than the others).


No astringency. Aroma and flavor with little texture. Still sweet even as it cools, though begins to taste a bit watery, as does A.

The Reveal

Spoiler alert! Don’t click the buttons below until you have finalized your guesses about which tea is which.

A – Ujeon. Even when cold this one is just different. Still retains a hint of white flower aromas and that refined sweetness that I just didn’t get from the others. No bitterness even when cool.

B – Daejak. The deeper heavier notes here make me think it’s the daejak, combined with noticeably more bitterness.

C – Joonjak. The slightly stronger grain flavors make me think this is the joonjak, though I’m not positive.

D – Organic 3rd pick. This one has some completely different flavors than the other and is much stronger in every way. I can only imagine this is the organic boseong.

E – Sejak. Having the hardest time differentiating between this and C.

A – Organic 3rd pick

B – Sejak

C – Joonjak

D – Ujeon

E – Daejak


How did you do? Better than me? I sure hope so – I basically did as well as probability would dictate. While I would have preferred to have guessed right, guessing wrong is a much better teacher. Here’s what I’ve taken away from this little experiment:

1) This is a great example of elevating perceptions above logic! Trusting my senses, I was able to differentiate that there was something different about A and D. A stood out for being light and fragrant, while D stood out for its intense flavors. Having very little experience with Korean green teas, however, I interpreted my results incorrectly. I thought that the ujeon would have the lighter floral aromas instead of the heavier, denser taste. If I had to guess, this might be due to the high temperature at which I steeped these teas. The ujeon, with its smaller and more fragile leaves, has more surface area from which things can be extracted more quickly. The organic 3rd pick tea gives a lighter brew simply because the leaves are larger, leading to less compounds extracted over time. This is probably also why I thought E (Teas Unique daejak) to be the sejak, following my line of thought that the more expensive teas would have the softer, finer aromas and flavors. This case of misinterpretation could have mostly been avoided if I had let the physics guide me instead of my preconceptions about the teas!

2) Following 1) above, I think it’s fair to say that some types of information gleaned from the teas during the tasting process are more important than others when determining grade. The least subjective information (the color of the liquor) was a good indicator of general leaf size, with all else being equal. The relative astringency in the texture of the teas also clearly separated the two finest picks (B and D, the sejak and ujeon) from the other three. The most subjective fields (like aroma and balance) contribute most to my personal enjoyment of the teas, but led me astray when I attempted to tie my enjoyment to a grade.

3) As I expected before beginning this trial, I had the hardest time guessing between the teas closest in price, the daejak and the joonjak. The teas look quite similar physically as well, so there’s no real surprise there.

So what’s next?

It would be interesting to perform this tasting again, but at a much lower temperature. Would the smaller bud teas (the ujeon and sejak) create a more balanced cup, with less astringency? Would the daejak/joonjak become more bland, if it’s the case that the high temperature water extracted particularly pleasant aromatic molecules?

Unfortunately, I’ve used up my samples of these teas! Have you done your own tastings across grades of teas? Let me know in the comments what you have found in your tea experiments!

Addendum - is it worth it to buy more expensive grades of Korean Green tea?

I can only unsatisfactorily answer, it depends what flavor profile you’re after, and how you plan on enjoying your tea. Based on the appearance of the dry and wet leaf, all of these teas seem to have been picked and perhaps even processed largely by hand. For teas with a finer pick (like the ujeon and sejak, which are mostly bud picks), this represents more plucks-per-gram (to coin a phrase?), more labor-hours, and higher base costs. But what about what ends up in the cup?

Let’s start with the ujeon. It is certainly different than the other teas. When I drank it on its own (using a much longer steep, but the same temp), I noticed much finer nuances and really enjoyed the tea. I don’t hesitate to say that knowing the price of something changes the experience of it, and this probably influenced me when creating my original review. But, the parameters were also different, and drinking a single tea versus five in one go also affects one’s perceptions and experiences. All this aside, yes, I think it’s worth it to try this tea because it’s unique. I wouldn’t drink it prepared the way I did here, but it certainly had a lot to give and would probably be a fun one to experiment with and figure out more suitable parameters.

As for the daejak and joonjak, they’re quite similar and justified in being so similar in price. If you’re just going to pour near boiling water on your tea, the daejak is great. The joonjak is great, too.

It’s interesting how different the organic boseong 3rd pick was from the Teas Unique teas of a similar grade. The floral aroma is wonderful and I can’t help but wonder where it comes from.

The sejak has hints of the ujeon’s characteristics, but is much closer in character to the others (daejak/joonjak), lacking the density/strength of the ujeon. If I’m not mistaken, the price reflects this as well. So in that case, it’s more of a personal preference.

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