By Ricardo Caicedo of MyJapaneseGreenTea.com (edited by Ian Chun)
You don't have to be an expert tea taster to tell if a Japanese green tea is of good quality or not. Just by learning the basics and with some practice, it's more than enough for the average tea enthusiast.
About tea tasting
There is a professional procedure to taste tea in Japan, and it's different than the ISO 3103 standard for brewing tea.
Perhaps a better term is tea evaluation, because it's not only about tasting. You have to pay attention to color, aroma, etc. In both standards, the tea isn't prepared in the same way that consumers would drink it. For example, boiling water is used for all green teas and the steeping time is longer.
However, unless you are a Japanese tea appraiser--someone being paid to evaluate the quality of teas for a finishing factory--there's really no point in doing the professional tea tasting.
I have studied the professional way, but I lack the practice. The only way to truly master evaluation of Japanese teas is by living in Japan and practicing often--tasting many, many teas over and over again. It will be useful if you were to go to tea auctions and the like, because you can detect small flaws in harvest, processing, etc. But realistically, if you just drink tea for the pleasure of it, or even if you are buying for your own tea business, I'm not sure if the investment of time and effort to learn the professional standard is worth it.
Instead, you can simply taste tea according to the way that you would brew it at home or might recommend to your customers. If your tasting skills are good, it will take you a long way toward becoming a better judge of tea, and make your and your customers' tea drinking more enjoyable.
Let's get started.
It's different for each type of Japanese tea, so let's concentrate on sencha.
The ideal (the most premium quality) is to have leaves that are tightly rolled in a narrow, needle shape. All the leaves should look uniform, if there are big leaves mixed in with small leaves it isn't as good. There should be very little tea dust. Also, stems and stalks shouldn't be present.
A deep green color with luster (shine) is desirable. It should look fresh.
Should be apparent, if there is almost no aroma then the green tea may be old.
The higher quality Japanese green teas such as sencha (especially shincha), gyokuro and matcha have an aroma of seaweed with a sweetness to it. It should also evoke freshness.
Wet Leaf Aroma
Should be refreshing, reminding of young buds. It should also have a marine component to it. Seaweed or even sea water.
For sencha, the color should not be too intense. Sediment should be minimal. There should be no red hue, only green and yellow.
Umami flavor and sweetness are desirable. There should be astringency and bitterness to evoke a refreshing flavor, but at a low level. The way that these four aspects interact will determine if the tea is balanced or not. A refreshing aftertaste is desirable.
How can you improve your tasting skill?
You have to practice, there's no way around it.
Try different samples of the same type of tea, and taste them in succession, paying attention to the differences. For example, it could be sencha from different regions, or a high grade sencha with a low level one.
Evaluate high quality teas and try to determine what the similarities are. That way you start to get an idea of what to look for.
It's very hard to put the nuances of flavor and aroma into words, so it can't be transmitted by an article. You must experience it.
If weeks go by without drinking Japanese tea, it becomes quite difficult. However, If you taste it often you will obtain the basic skills quickly.