• HOME >
  • How to enjoy tea

Pu-erh tea compression

Why is Pu-erh teas compressed? A common answer to that question would be to minimise the volume and for effortless transportation of tea. However, there is another reason that is not widely known.

No oxygen is an ideal environment for maturing Pu-erh tea

I have conducted an experiment of keeping Pu-erh tea for maturation. I analyze the tea condition after keeping the Pu-erh teas in different conditions where some were exposed to ambient atmosphere, some vacuumed, and some using an oxygen absorber to remove 100% of oxygen. As a result, the tea that was kept without oxygen matured in the most ideal way. The Pu-erh tea kept in an exposed condition to the ambient atmosphere absorbs the moisture present in the air; developing some mold on the surface or emitting unpleasant musty odor. On the other hand, the Pu-erh tea that was kept without oxygen developed a sweet flavour that reminds me of honey, and it produced the sweet fruity or sugarcane-like flavour with further storage. Based on these experiments, I have concluded that it is necessary to keep Pu-erh tea without oxygen in order to get it matured very well.

The maturation is different from fermentation

There are some people who insist that the maturation of Pu-erh tea is a process of “fermentation”. However, I absolutely disagree with it because fermentation refers to the chemical reaction that is mediated by enzymes. However, the tea that is vacuum packed contains very low moisture that is insufficient for any enzymatic reaction to occur. However, if tea is kept inside a room with high humidity, it will immediately be contaminated by microorganisms such as mold and bacteria. Furthermore, some inappropriately kept Pu-erh teas would produce musty or earthy flavour if any of them were actually contaminated by the microorganism during storage. Of course, there is a big question mark whether or not it is safe to consume.

The maturation of tea involves no enzyme and no microorganism

Maturation of tea is neither by enzymatic reaction nor microbiological fermentation; but, it involves a non-enzymatic oxidation and reduction process which occurs by altering the constituents in tea leaves. When tea is exposed to the oxygen in the atmosphere, it triggers excessive oxidation. As such, tea will be nothing but oxidized and spoiled. Hence, an ideal environment for having tea matured is without oxygen; yet, one may wonder how would the tea be matured or oxidized when there is no oxygen. In chemistry, there are three definitions for oxidation which are as follow:

  1. Receive Oxygen
  2. Release Hydrogen
  3. Release Electron

As you can see from the above three definitions, we do not really need the oxygen in the air to carry out the maturation (oxidation) process. If you wish to learn more about the definition of the oxidation, please refer to the following page:
http://www.chemguide.co.uk/inorganic/redox/definitions.html

Both compression and suction can remove oxygen

Let’s rewind back to the reason why we need to compress the Pu-erh tea. Usually, if one wishes to completely remove the oxygen that exists in the tea leaves, it is either vacuum it or compress it very hard. Both compression and suction could eliminate the oxygen if the pressure is strong enough. Most of the Pu-erh tea manufacturing places in Yunnan are located deep inside the mountains where it sometimes take more than 20 hours by local bus from Kunming to reach the destination. The idea to compress tea originates from the wise ancient Yunnan folks who wanted to be certain that oxygen was completely eliminated from the tea; moreover, the compressed teas enable a more convenient transportation. Although, the leaves at the surface of the Pu-erh cake will definitely be oxidized; however, the volume of the tea leaves at the external layer of the cake is considered as a very minor amount which is small enough and negligible.

pu-erh tea

The Pu-erh tea cake used to be compressed very hard

About 20-30 years ago, the Pu-erh tea was often compressed extremely hard that it was known as the “iron bing” (铁饼). It was compressed as hard as a piece of stone that one cannot even break it using a knife or a strong eyeleteer. Based on my experience, all the iron bing Pu-erh tea was ideally matured no matter how it was kept. Thanks to the hard compression, there was no oxygen remaining inside the leaves. These teas produced sweet flavour like dried fruits which I enjoy drinking them so much. Unfortunately, nowadays most of Pu-erh teas are not compressed like an iron bing anymore. If we compress our tea too hard, we would receive a number of complaints from the customer saying that it is really very hard to break apart the tea for drinking. Generally, nowadays most of tea companies compress Pu-erh tea moderately, which will definitely leave some oxygen in the tea leaves. Under the circumstances, tea will get oxidized no matter how it is kept.

Based on the above logic, we pack tea with an oxygen absorber that is made of the reduction iron powder. This will absorb oxygen as iron absorbs the oxygen from the atmosphere to form iron oxide. We are quite satisfied by this method since we can get the tea well-matured in a right environment and at the same time, the Pu-erh tea cake will not be too hard to cause nuisance to the customers.

Related Articles

How to get the latest update on HOJO Tea?

1. Follow Twitter, 2. Click "Like" on Facebook, and 3. Subscribe in newsletter. You can have the latest tea news from HOJO Tea.

Subscribe the Newsletter to enjoy the privileges
You may receive a free sample upon purchase, or you may have the priority to purchase special products. So please remember to subscribe our newsletter as well as the social network.
  •                 

HOJO TEA Online Shop NEWSlist

Taiping Houkui 2019 is now available in our store
2019 Taiping Houkui is available in our store. Taiping Houkui was listed as the Top Ten Famous Teas in China. It has been the well-known green tea of Anhui province since Qin dynasty. We have both standard and special tribute grade. The special tribute grade was grown at higher altitude and it gives longer lasting …
2019 Chinese Green Teas are available in our store
We have now received three types of 2019 Chinese green tea and one yellow tea. Thanks to less rain in this spring, the quality of these teas is excellent. Shi Feng Long Jing 獅峰龍井茶 Long Jing is the well-known Chinese green tea. It is produced in Zhejiang Province. In particular, Shi Feng Long Jing produced …

NEW ARTICLES

Taiping Houkui 2019 is now available in our store
2019 Taiping Houkui is available in our store. Taiping Houkui was listed as the Top Ten Famous Teas in China. It has been the well-known green tea of Anhui province since Qin dynasty. We have both standard and special tribute grade. The special tribute grade was grown at higher altitude and it gives longer lasting …
2019 Chinese Green Teas are available in our store
We have now received three types of 2019 Chinese green tea and one yellow tea. Thanks to less rain in this spring, the quality of these teas is excellent. Shi Feng Long Jing 獅峰龍井茶 Long Jing is the well-known Chinese green tea. It is produced in Zhejiang Province. In particular, Shi Feng Long Jing produced …
Pre-Booking of Da Xue Shan Wild Tea and White Tea Mao-Cha 2019
We open the pre-booking of Da Xue Shan Wild Raw Pu-erh Tea and Wild White tea in loose form (mao cha). This year we have very limited stock of loose tea. We will close the booking once the quantity of order reaches our quota. Tea is arriving soon in Japan. So, we should be able …
The Field Report of Yunnan Tea in 2019
We have been staying in Yunnan since 9th of April for sourcing spring tea. In previous years, we usually came here before the end of March. This year, we shifted our schedule about 10 days later since we wanted to stay here until the end of spring tea season. This past week, we were engaged …
Limited Release of Rare Single Tree Pu-erh, White and Black Tea
We have opened the sales of Single Tree Tea (Dan Zhu Tea) produced in 2018 spring. Single Tree Tea refers to the selected tea produced only from one particular tea tree. It is considered as the most exclusive quality of all. For oversea customer, please visit the following page. https://hojotea.com/en/posts-213/ So far in Yunnan, only …
New Release of Vintage Guo Gan Ripe Pu-erh Tea
We released very rare and limited ripe pu-erh tea. It is 9 years vintage ripe pu-erh tea from Guo Gan in Myanmar. It gives distinctive vintage tea flavour with a hint of dry-fruity flavour and herbal-like aroma. Tea grown in Myanmar-China border town Guo Gan is the place in Myanmar facing to Yunnan, China. This …
New Release of High Mountain Purple Black Tea 2018
We have released High Mountain Purple Black Tea 2018. This tea is one of the very popular Yunnan black tea in our line-ups. Since it is a very cold season now in Japan, this tea suite very well. I often enjoy this tea recently. Purple Tea variety gives very special flavour The high mountain purple …
Tsukigase Sencha Processed with Long Withering
We made an interesting green tea with Tsukigase’s spring tea. It is sencha, and we conducted long withering process to enhance its flavour. As a result, it gives a gentle floral scent that reminds me of Taiwan’s lightly fermented oolong tea. After producing tea in spring, in order to further enhance its flavour, we kept …
Cha Tou Brick 250g from Hou Cao Shan is available
We released Huo Cao Shan Cha Tou Brick 2017. This Cha Tou is from the same batch of tea we released earlier on pre-booking. Despite tea was produced about one year ago and not aged for a long time, it already gives very soft, mellow and rich drinking sensation with thick fruity flavour like Chinese …
The Secret of Jasmine Flower for Making Fine Jasmine Tea
Jasmine tea is made from green tea scented with the fresh jasmine flower. The quality of both green tea and jasmine flower is important. Jasmine tea consists of various cultivar and variety. The type of jasmine and the timing of plucking greatly affects the quality of jasmine tea. Heng Xian County of Guangxi is the …

PAGETOP