Puerh Education: Grade of Leaf January 15 2015

Puerh is complex. That is an understatement if there ever was one. The complexity of puerh is a large part of what fascinates me and many others who pursue the mysteries of this, the darkest of brews. Puerh has a history spanning a millennia and a half; probably longer. Puerh was traded as a commodity on the Tea Horse Road for 5 centuries before the British had even heard of tea. Part of what makes puerh complex is this rich history, but it is just as complex by the very nature of itself. Since you can age puerh it is always changing. The bacteriological fungal fermentation is continuously modifying the leaves. This creates a moving target for understanding puerh.

Additional variables only add to the complexity. Which mountain were the leaves picked from? How old were the trees? What time of year were the leaves picked? How were the trees fertilized? Did the trees grow naturally, or were they part of an organized plantation garden? Who picked and processed the leaves? What was their skill? Was the puerh compressed into cakes, or left loose as maocha? How tightly were the cakes compressed? Which grade of leaves were used? Then finally one of the most important variables; how and where were the cakes stored? Were they stored in a hot and humid environment, or a cold and dry one?

Puerh remained largely unchanged until the 1970’s. Modern customers didn’t want to wait for puerh to age so they created methods to artificially increase aging time through scientifically controlled methods. What they created was a new type of puerh. It’s not really a replacement for traditionally stored and aged puerh, but something unique in its own right. This is shou puerh; also called ripe or cooked puerh. Even though there is no actual cooking involved, the term cooked has stuck in the western markets. The process to make shou puerh is called ‘wodui’. To simplify a complex process it is more or less treated like a compost. Large piles of already processed sheng puerh (maocha) are allowed to ferment in large rooms with controlled temperature and humidity. For good reason many factories keep the exact details a well kept secret. Were the exact details for Dayi’s famous recipes to get out it would mean a direct impact to their bottom line.

One interesting part of our trip last year was working with the China Puer Tea Research Institute. They’ve been around almost 30 years. Their full name is the China Puer Tea Research Institute Tea Seed Multiplication Farm of Simao/Puer Yunnan or CPTRTSMF for short. The highly specific nature of naming in Chinese culture always amuses me! CPTR is a government sponsored research organization whose sole focus is puerh tea. They are largely farmer focused and exist to aid farmers in any way possible. Many of the research projects they started 30 years ago are just now showing results. They are based in Puer City, Yunnan. Yang Liu Xia is the woman who has run CPTR for 25 of the last 30 years. We met with her last Spring and she was a wealth of information. We toured the CPTR puerh research labs and gleaned as much information from her as possible.

I thoroughly geeked out while touring their research labs. They had an impressive setup with some very expensive chemical analysis hardware that I would love to play with for a few days. They also had a fascinating entomology department that had mounted examples of all the tea related insects in Yunnan. One wall was for the insects known to be beneficial to growing tea plants. The other wall was for insects known to be harmful. It was an impressive collection. Some of the insects were horrific in a way that only H.R. Giger could conceive of.

This monstrous insect is wider than the span of my hand and is considered harmful to the tea trees.

About 10 years ago the CPTR decided to focus some energy into a commercial venue. This would have two benefits. They would be able to supplement their research budget and also be able to test their findings on the commercial market. They created a division called “Paka” with this focus in mind. Paka is a name taken from the native language of the Yi minority and means "Old Tea Tree". One of the first cakes that we sold in our store was a 200g mini bing from 2011. This was a special cake because the CPTR was awarded the Golden Prize in the 2011 Yun Xiang Bei (Cloud Aroma Cup) Annual Competition in the category "Puerh Shou Cha". It’s not an amazing shou puerh, but it’s quite nice and very drinkable.

While we were in Kunming the Spring of 2014 I wanted to make sure that we picked up some more of this award winning cake to sell. While meeting with the Paka representatives I noticed what I thought was a peculiar setup. I saw stacks of identically wrapped cakes on a shelf whose difference was simply the numbers 1, 2, 3, and 4 ( 一, 二, 三, 四 ) in Chinese stamped on them. My curiosity piqued I asked about them and was told that these were the last of a series of experimental cakes the CPTR had done research with in 2010. Each number represented a different grade of leaf. I was immediately intrigued.

When one endeavours to understand a thing like puerh it is critical to remove as many variables as possible. You need to narrow down. Comparative analysis is most beneficial if you are testing one variable against another. I spent years working in IT doing helpdesk/onsite support. I then spent many more years doing Quality Assurance for large software projects. In each role I was most successful when I could remove extraneous variables and strive towards an A / B comparison. Understanding puerh is like troubleshooting a modern computer system. 

When a system is too complex it is hard to fully understand the underlying pieces. Why does Dayi, or other companies, use the recipe they use for their classic puerh cakes? Why do they add more lower leaf grades to some recipes and more higher leaf grades to other recipes? To answer these questions and begin to understand puerh we need to remove extraneous variables. Tasting different blended puerhs will only cause more confusion unless you can remove variables and focus on small changes. With the CPTR research cakes I saw a unique opportunity. I could remove many variables and focus solely on how leaf grade changed the tea. With these cakes the variables of region, farm, production method, tree age, processing methods, and post processing storage methods were all identical and therefore cancelled each other out. Focus can be given to the grade of leaf.

This excited me greatly. There are rare opportunities to experience something like this unless you are local to Yunnan and involved in puerh production. Adding to the excitement was the notion that since these cakes were made in 2010 that the findings from this unique research was directly used in the production of the 2011 award winning Paka cakes. I knew we had to have these cakes and I bought all that they had. My hope was to be able to bring these back to the States and create a product that would let students of puerh outside of China access to these incredible training tools.

After I expressed interest in the 2010 CPTR shou puerh research cakes I was shown an identical set for sheng puerh created the same year. Sadly, only grade 2, and 3 were left. Grades 1, and 4 had been sold. It took us a couple months before we were able to track down those other cakes to have complete sets. I’m happy to say that we have complete sets for each available.

Puerh is generally graded on a 0-9 scale. Grade 0, or ‘imperial grade’ is just the buds and grade 9 is the largest leaves. There is no top or bottom to the scale and each grade exhibits different properties. The longer the leaf is on the tree the larger it is and also the more minerals will be present. It has also been more affected by the sun. The CPTR numbering convention doesn’t line up with the traditional methods. They set out 4 categories based not on leaf size but on plucking standard. That means that their Grade 1 consists of 1 bud, and 1 leaf. Grade 2 is 1 bud, 2 leaves. Grade 3 is 1 bud, 3 leaves. Then Grade 4 is 1 bud, and 4 leaves. These are hand picked and left on the stem.

All leaf material is from CPTR’s private organic tea research garden in Simao. Their trees average 25 years in age. There is a mix of Summer and Autumn leaf with a little Spring. The sheng puerh research cakes have had the least amount of processing done to them. They were pan fried and sun dried separately by grade. When enough maocha was prepared they worked individual wodui processes to convert the finished maocha into shou puerh. The wodui process is tricky and is different depending on amount of leaf, grade of leaf, and ambient seasonal temperature and humidity during the wodui process. Wodui started in Winter takes longer than the same process with the same leaves started in Summer.

I have spent time with these educational sample sets and they are intriguing to say the least. My biggest fear was that they would all taste the same to untrained palates. I was very happy to find that the differences are clear to see between the grades. I’ve done tea tastings with tea novices who were all able to ascertain and appreciate the unique qualities present in the different grades. Doing taste testing with 4 gaiwans and each sample side by side is a truly educational experience. I won’t spoil the surprise and let you do your own tasting research and experimentation.

We are making these sample sets available for everyone to experiment with. Each set contains 10g samples of each of the 4 grades of leaf. They're only $15. We have one set for sheng puerh and one for shou puerh. Take the 4 grades and brew them side by side. After you’ve experimented with the uniqueness of each grade try mixing it up. Brew some from each grade and then mix that brew with the others. Try say 75% of Grade 4 with 25% of grade 1. Learn to create custom blends. This is what the tea masters in Yunnan have done for a millennia. Create your own recipes. Take notes. Learn and enjoy the amazing world of puerh!


It's very easy to see the difference in leaf grade below when viewing each cake side by side. Grade 1 is brighter and contains more buds with downy soft hair. Grade 4 is noticeably darker and contains more large leaf and stems.

Sheng Puerh

Shou Puerh

These images are a comparison of cake thickness. Sheng puerh is the stack on the left and shou puerh is the stack on the right. It is interesting to note how much thicker the larger grade cakes are. It's most noticeable for the shou puerh cakes.

All images © Crimson Lotus Tea 2015