Tea Identification Methods: Teaching You to Tell Good Tea from Bad

As a worldwide beverage product, tea has no fewer than three thousand varieties, and famous teas are too numerous to count. Such as West Lake Longjing, Dongting Biluochun, Lushan Yunwu tea, Nanjing Yuhua tea; and also Pu'er, Tieguanyin, Shuixian tea, Dancong Fenghuang tea, Kuding tea and the panda among plants - Jinhua tea, and among black teas Yinghong, Dianhong, Qihong; all are outstanding famous teas, and the quality and price of tea also differ greatly. There is coarse tea at a few yuan per jin, and also supreme tea at over a hundred thousand yuan per jin. Therefore, the purchasing and sales departments in the business world. Have set very detailed grade standards, striving to give a reasonable price as far as possible. But in a market economy, counterfeit famous and superior goods or adulteration often occur. If the tea purchasing and sales departments and consumers lack identification ability, besides being deceived, they will also suffer huge economic losses. Especially the business world and their supervisory and inspection departments more urgently need a simple, accurate, and easy-to-operate scientific testing method. To crack down on the illegal adulteration practices of speculators who pass off fake goods as genuine and inferior goods as superior. In order to safeguard the interests of the state, production enterprises and consumers.

There is very little material on tea identification methods. What has been publicly published is only an article titled "Identification of True and False Tea" published two years ago in the magazine "Nutrition and Food Hygiene". The article introduced two methods:

1) After brewing the tea with boiling water, inspect the number of small serrations on the edge of the tea leaves; those with 20-30 small teeth are true tea, otherwise they are false tea.

2) After the brewed tea is cooled, if there is a bright film (more obvious after overnight), it is true tea; if there is none, it is false tea.

Although these two methods have a certain scientific basis, their shortcomings are that they take too long, and their specificity and sensitivity are insufficient. When encountering the tea bags, instant tea and canned tea widely popular on today's market. They do not have complete tea leaves for you to count teeth, nor can you wait that long to see whether a "bright film" appears. This shows that from a practical point of view, people still need or are still calling for faster, more accurate, and more operable tea identification methods. To determine whether it is true tea and the quality of tea, methods such as paper chromatography, colorimetry, gas chromatography, high-pressure liquid chromatography and automatic amino acid analyzer methods, which belong to physicochemical analysis, can be used for determination. As for the originally effective sensory analysis in the tea industry, inspecting whether the tea is pure, uniform, and whether it has the unique fresh fragrance of tea and its degree of richness (color, aroma, taste, shape)..., it is not necessary to abandon all of it; how much should be retained can be discussed by peers and experts in the tea industry.

Color, aroma and taste often vary from person to person, and it is relatively difficult to make an accurate judgment. Using physicochemical analysis methods - the ninhydrin determination method to measure theanine and the total amino acid method, it can identify whether it is true tea and the category and quality of the tea. For the determination of theanine and total amino acids in analysis, an automatic amino acid analyzer is generally used. As long as the sampling is representative, after brewing a cup of tea and extracting three times, sampling and running it on the machine for about 2 hours will produce detailed results. Those without an automatic amino acid analyzer can use methods such as paper chromatography, colorimetry, gas chromatography, and high-pressure liquid chromatography for determination.