Pu'er tea before 2006 had almost no formal anti-counterfeiting code. Products that claimed to have "laser anti-counterfeiting in the 1990s" were essentially time-travel dramas of modern technology. The real historical imprint is hidden in the packaging details: Hong Kong warehouse tea before 1995 had irregular "worm bites" on the edge of the cotton paper, which was a trace of bamboo borers unique to Southeast Asian warehouses; state-owned factory tea around 2000 had the "Bazhong Tea" trademark green print on the inner fly. Under a 40x magnifying glass, you can see that the ink particles are distributed in a honeycomb shape, while fakes mostly use smooth digital printing.
According to the 2024 spot check data of the China Tea Circulation Association, 67% of the "90s old tea" cotton paper on the market has a pH value of less than 5.5, while the pH value of cotton paper that has been naturally aged for 20 years should be between 6.8-7.2 - too strong acidity means that sulfur-containing fumigants were used during artificial aging. A more hidden trap is the "wet storage to dry storage" tea, which will have extremely fine white mycelium remaining on the back of the cotton paper. This is the metabolic product of Penicillium fungi in a high temperature and high humidity environment.
In the 2003 Kunming Tea Factory's "Ban Zhang Qingtuo" inner fly, the blue ink at the factory director's signature will show a special Fe³+ absorption peak under the infrared spectrum, which is a unique component of the blue-black ink produced locally in Yunnan at that time; while the imitations after 2010 mostly use modern carbon ink, and the spectrum does not have this feature at all. In a million-level fake tea case cracked by a judicial appraisal center, the counterfeiter actually tampered with the date of the 2015 test report to 1998, but did not notice that the fluorescent brightener on the paper was not popular before 2000.
The anti-counterfeiting of old tea bills is more like a historical puzzle: the delivery notes of Hong Kong tea merchants in the 1990s must be in traditional Chinese vertical format, the amount unit is Hong Kong dollars and is stamped with a saddle stamp; the factory orders of state-owned factories in 2000 have a numbering rule of "year + batch + category code", such as the batch number 7542 in 2001 will never have mixed letters. Those products that come with a "Forbidden City certification" are nothing more than scam props customized for 30 yuan on Taobao.
Scanning electron microscope images from the Kunming Institute of Botany, Chinese Academy of Sciences, show that the cell walls of the mesophyll cells of Pu'er raw tea aged for more than 15 years will have unique "turtle cracks", which are the product of the slow degradation of cellulose during the oxidation of tea polyphenols; and the leaf bottom of the old tea shows irregular fracture surfaces under the electron microscope, which is evidence that the cells burst instantly due to high-temperature baking. The more critical indicator is the "carbonization degree of tea stems" - the center of the tea stems of real old tea is light brown, and fine annual ring-like fibers can be seen when broken, while the fake tea stems are mostly completely carbonized and burnt black.
The sensory identification formula "three looks and three pinches" is circulated among Menghai tea farmers: First, look at the buds. The fluff of the old tea buds is silvery white and the roots are reddish, while the fake tea is mostly grayish white or pure black; second, look at the leaf edges. The edges of naturally aged leaves have irregular gaps (caused by insect bites or oxidation), while the edges of old tea are neat and sharp; third, look at the toughness of the leaf bottom. After brewing, the leaf bottom of real old tea will not break after folding three times, while the fake tea will become dregs with a pinch. Experimental data from Yunnan Agricultural University show that the accuracy of this identification method can reach 89.7%.
The truth revealed by the gas chromatograph is shocking: the fake tea that claims to have "20-year aged fragrance" has 37 times more benzaldehyde in its aroma components than the standard - this is a sign of artificially added flavors; while the real old tea will generate unique β-ionone (the main substance of aged fragrance) and terpene compounds during the aging process, and the content increases exponentially with the age. The "Tea Fragrance Time Calculator" developed by the Olfactory Laboratory of the Hong Kong Polytechnic University can accurately judge the aging year with an error of no more than 3 years through the ratio of 17 characteristic aroma molecules.
Advanced skills of traditional scenting method: When smelling dry tea, the aroma of real old tea is "calm wood fragrance with a hint of honey", while the old tea has a pungent sour and rancid smell (excessive wet storage) or burnt smell (high temperature baking); the cup fragrance lasts for more than 30 minutes after brewing, and the cold smell of the fair cup has a distinct "rock sugar sweetness", which is a natural anti-counterfeiting mark given by time.
Spectral analysis by the Optoelectronics Laboratory of Zhejiang University shows that the tea soup color of raw Pu'er tea aged for more than 10 years has a unique absorption peak at 460nm, which is a special conjugated structure formed by the oxidation and polymerization of tea red pigments; while the fake old tea with caramel color added has strong absorption at 510nm, which is the characteristic peak of food pigments. A more clever identification point is the "dynamic change of soup color" - the color of the real old tea changes from orange-red to amber from the first to the tenth infusion, and it always remains transparent; the color of the fake tea is as dark as soy sauce in the first three infusions, and it quickly becomes lighter and turbid after the fifth infusion.
The "cup hanging effect" of tea soup also hides a mystery: when the real old tea soup is stirred with a glass rod, the wall of the cup will form fine and uniform "tea tears", which is the physical manifestation of rich tea polysaccharides and amino acids; the "tea tears" of fake tea soup are coarse and intermittent, mostly due to thickeners. Experiments by the Guangdong Tea Inspection Institute have shown that this method combined with soup color spectral analysis can achieve an identification accuracy rate of 94.2%.
The signals captured by the taste sensor matrix show that the taste of old tea is a perfect balance of "sweet, smooth and moist", among which the key indicator is the theabrownin content (5-8% is the normal aging range), while fake tea has more than 12% theabrownin due to rapid oxidation and is accompanied by a large amount of harmful aldehydes. Volunteers from the taste laboratory of National Taiwan University found that after drinking real old tea, the activity of salivary amylase in the mouth will increase by 23% within 30 minutes. This physiological reaction of "sweetness and fluid production" can never be imitated by artificial old tea.
The "throat rhyme experience" when tasting is the ultimate test: after swallowing the tea soup of real old tea, there will be a noticeable cool feeling in the throat (commonly known as "deep throat"), which can last for 2-3 hours; while fake tea mostly stays on the palate of the mouth, accompanied by a dry or locked throat feeling. Physiological experiments at Yunnan University of Traditional Chinese Medicine have confirmed that the generation of throat rhyme is related to the stimulation of the vagus nerve by terpenes in the tea soup, which is a unique neural reflex given by time.
Guangzhou Customs once seized 10,000 tons of fake old tea, which generally adopted the quick method of "high temperature and high humidity + sawdust fumigation". This process will cause aflatoxin B1 to exceed the standard by 200 times. The key to identification lies in the "warehouse smell layering": the storage smell of real dry warehouse old tea is a refreshing "camphor wood fragrance" or "stale warehouse smell", while wet warehouse tea has obvious "musty smell - sour smell - burnt smell" three layers of odor, which is the product of excessive reproduction of Penicillium, Aspergillus niger and Alternaria. Fungal detection by the Institute of Microbiology of the Chinese Academy of Sciences shows that the number of mold spores per gram of tea in healthy warehouse old tea should be less than 500 CFU, while wet warehouse tea generally exceeds 5000 CFU.
The more concealed "semi-dry warehouse" counterfeiting will be artificially dried after wet warehouse treatment, and irregular dark brown spots (mold mycelium residues) will remain on the back of the leaf bottom, while the color of the normally transformed old tea bottom is uniform, and the back of the leaf is light yellow to dark brown. The "warehouse turnover diary" of Hong Kong tea merchants revealed that with true natural aging, the weight of tea cakes will decrease by 0.3-0.5% each year, while the weight of aged tea will fluctuate by more than 2% due to the repeated inflow and outflow of moisture.
The emerging "irradiation aging" technology accelerates the oxidation of tea polyphenols through cobalt 60 rays, and the γ-aminobutyric acid content in the tea soup will be abnormally high (more than 0.8mg/g), while the index of naturally aged old tea should be less than 0.5mg/g. The more primitive "iron pan frying" process will cause the content of pyroglutamic acid in tea to exceed the standard. This substance is generated at high temperature and has potential neurotoxicity. Risk monitoring by the Yunnan Product Quality Supervision and Inspection Institute shows that 12% of "old tea" on the market in 2023 has traces of irradiation or over-baking.
The ultimate rule of process identification is "counter-common sense verification": if a so-called 20-year-old raw Pu'er has a red and thick soup color like cooked Pu'er, it must be the product of artificial piling, because the soup color of naturally aged raw Pu'er should be orange-red and bright rather than dark red; if the 30-year-old cooked Pu'er still has a clear pile flavor, it means that industrial yeast may have been used to accelerate the conversion during the fermentation process. The real old cooked Pu'er should present a mellow "medicinal fragrance + jujube fragrance".
Unveiling the mystery of a fake tea factory in Shenzhen, you will see a complete industrialized aging production line: the first step is high-temperature baking with a drum-type tea roasting machine (simulating natural oxidation), the second step is spraying "aging fragrance" (the main ingredients are benzaldehyde and ethyl maltol), the third step is to put it into a customized "wet warehouse" (a stainless steel box with controllable temperature and humidity), and the fourth step is to manually polish the cotton paper with sandpaper to create "traces of time". More advanced counterfeiters will purchase the inner fly and packaging of real old tea, put in new tea and re-press it. This kind of "Li Dai Tao Jiang" type of counterfeiting is difficult even for senior tea drinkers to distinguish.
According to a survey report by the China Tea Circulation Association, among the products marked as "middle-aged tea" on the market in 2024, only 13.7% are in line with the real aging year, and the remaining 86.3% are counterfeited to varying degrees. The hardest-hit areas of counterfeiting are concentrated in Guangdong, Fujian, and Yunnan, forming a complete industrial chain of "raw materials-processing-packaging-sales", with an annual output value of more than 20 billion yuan. What is even more worrying is that some counterfeiters have begun to get involved in the field of ancient tree tea. Through the "grafting" technology, they graft branches of terraced tea onto ancient trees to create "half-real, half-fake" high-end fakes.
In this era dominated by "fast-moving consumer goods thinking", the core value of middle-aged and aged tea lies precisely in resisting quick success - real old tea is a masterpiece of sunlight, soil, microorganisms and time, and each piece of tea carries the code of years. When we learn to examine the stories on the packaging with a scientific eye and treat the myths of hype with a rational attitude, those old teas that have quietly transformed over time will eventually open their arms to those who truly understand it with a unique taste and physical sensation.
The process of identifying old tea is essentially a dialogue with time. Remember: there is no shortcut, but there is no need to panic. When you master the four-dimensional identification method of packaging, dry tea, tea soup, and warehousing, and when you learn to use the power of scientific testing, those fakes that try to get away with it will eventually show up under rigorous scrutiny. After all, time can be imitated, but it can never be forged.
Focusing on Pu'er ancient tree tea for 17 years, we will help you understand Pu'er tea in a simple way
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