Monday, March 12, 2012

Puerh FAQ and Resource Guide for Beginners

(Hey!  New springtime look!)  I often meet people who are new to puer and eager to learn.  It can be an initially bewildering exploration that I remember all too well when I was new to puerh myself.  So I thought I'd put together a sort of "where to begin" to help with those first steps on the journey.  Please note I've embedded links throughout the text below.  Feel free to add links and info if you're so moved.

What's the difference between cooked, raw, ripe, green, sheng, and shou puerh?

There are essentially two kinds of pu'erh, and each kind is referred to in a number of ways (not unlike the various English-version spellings of puerh/pu'erh/puer/pu'er).  Raw puer can also be referred to as green, sheng, or shengpu.  Ripe puer is also referred to as cooked, shu (or shou), shupu (shoupu), and on some vendor's site I've seen it referred to as black puerh.  The difference between the two is how they're processed, with ripe puerhs undergoing a fermentation period before being pressed into cakes.  Good basic intros to pu-erh can be found around the web, including this page on the Bana Tea Company website.  Another site with multiple pages and lots of in-depth information can be found here at  For some true knowledge and insight on how puerh is processed, see this great overview at ZhiZheng Tea's website, or this blog entry from Essence of Tea. Or you can scroll down to the comments for an interesting discussion.

What's the best way to brew puerh?

There are plenty of how-to guides on the internet.  YouTube videos, too.  Some "how to" links can be found here, and here, plus numerous other places, all with varying advice.  My suggestion is to begin conservatively, and always, always "listen" to the leaves.  Keep in mind the taste and experience of a puer is greatly affected by how it's prepared -- what temperature the water is, the leaf-to-water ratio, the length of steeping time, the type of equipment and water you use, even the weather and your mood will affect the taste and experience of a puer.  Generally speaking, the cooler the water and shorter the infusion times, the less likely you'll end up pulling harsh qualities from the tea.  Get good-sized samples (25 grams or so) so you can prepare several sessions with a particular tea and try brewing it in different ways.  You'll develop your brewing technique quickly that way.

How much leaf should be used?  A common guideline is 6-8 grams, but really it's all dependent on the size of your brewing vessel (and also, to some extent, the character of the tea).  Experiment and learn :)

Do a first rinse of the leaves.  Most people discard this water because it's usually very weak, but as you're beginning I would suggest taking a little sip just to aid your knowledge.  With some teas you might want to do two rinses, particularly if it's an older puerh that's starting off with a lot of funky/musty storage smell or taste.  When I first started out I spent a lot of time puzzling over just how long I should let the leaves sit in the water for the first rinse.  Over time I've found it helpful to consider the age and processing of the tea.  Younger, newer shengs still have a lot of moisture and flexibility in them and will respond and open quickly in the water, while older puers are drier and more "set in their way" and so will benefit from a little patience to coax them to open.  With very well aged puer I often let the wet leaves sit for a few minutes in the warm covered pot after the rinse to allow them time to relax and begin to open.

Water temperature and steeping times?  Keep in mind the general guidelines above and develop your own experiential sense of how the leaves respond.  You may find that newer, younger shengs appreciate not-quite-boiling water at first (but don't take my word for it, learn for yourself.. not all young shengs are alike).  You might do your first (drinking) infusion at only 3-5 seconds to gauge whether this particular puer will accept more aggressive brewing, or if it's happy to reveal great strength with just a few seconds of infusion time.  By all means, don't start your journey into puer with your first steeping at 30 seconds or longer (not unless you like a tea that punches you in the mouth).  Be gentle.  Get to know the tea you're brewing.  There's a whole world of complexity and nuance to be found in shorter steeping times, especially with those first few infusions.

still life with gaiwan and seashells
What equipment do I need?

To start, all you really need is a kettle to boil water, a vessel to brew in, and a cup to drink from.  Brewing puerh does not require a lot of gadgetry to be enjoyed.  As you grow and learn you may want to add some more implements.  Here's a rundown of tea gadgetry:

Brewing vessel:  You have options here.  The two most common vessels for brewing puerh are the gaiwan and the yixing (unglazed clay) teapot.  For the beginner to puer I would suggest a gaiwan.  You'll be drinking mostly younger sheng to start out and a gaiwan is really the perfect vessel for these.  In addition to being easy to use, it highlights aromas and potential sweetness of the tea.  Another great thing about a gaiwan is that you can easily observe the leaves as they open and soften which is good knowledge to have.  A gaiwan is not a "beginner's vessel."  It's a valuable tool you'll turn to often throughout your practice.

The yixing teapot is the other common brewing vessel.  You can find them for sale all over, at prices from very cheap to prohibitively expensive.  If you read tea blogs or forums like TeaChat you'll hear talk about "fake" yixing pots, although it's often unclear just what that means.  But rather than worry whether a yixing is fake or real, let your nose and palate be your guide.  If your yixing contributes a chemical taste or smell to the tea, get rid of it.  Some yixing teapot manufacturers will add chemical colorants to the clay (either to the body of the clay or the surface of the pot) in order to mimic the typical yixing clay colors or give it a sheen or aged look.  If you read around the TeaChat forums you'll find many discussions about yixing pots and recommendations for vendors who sell reliably good ones.

some of the yixing available at Best Tea House in Canada
Yixing teapots are a great match for puerhs that have some age to them (although I do sometimes use a gaiwan with older puerh if I'm in the mood for those qualities that a gaiwan will highlight).  A well-seasoned yixing will add depth and nuance to the tea and help to mellow harshness.  I also like the tactile quality that good yixing adds to a tea session.  There's something very satisfying about the feel of the pot, the warmth and texture of it, the flow of the pour, the tea soup drying on the surface.

Cup:  Find a good tea cup that fits your hand well and is just the right size, but do try out different cups as your experience grows.  I started with a frosted glass teacup because I liked how the color of the tea would glow through.  Then I acquired a couple of artisan-made cups, including a larger, wide, shallow cup made by Petr Novak which I loved for how it required the use of both hands to drink from, giving the sense of the tea being an offering to my mouth (also, the interior glaze was beautiful to look at as I drank, and it was the perfect size to hold a full pour from the teapot).  Lately I've become enamored with old porcelain, particularly these cups from The Essence of Tea.  The shape of them seems to enhance the gold ring effect of some teas, and their translucency allows light to penetrate in truly mesmerizing ways.  The tea liquid seems somehow more silky from them, as well.

Kettle:  For boiling the water.  Many options here, and an area I'm only beginning to explore.  Until recently I used an electric stainless steel pot, but in the coming months will be trying out a tetsubin, a clay kettle, and playing a bit with fire (charcoal heat).  Recently I was lucky to acquire a beautiful old Japanese jun-gin silver teapot, so will be learning about that as well.  Stay tuned...

That's really all you need to start -- a kettle, a brewing vessel and a cup.  But you'll soon find a few more additions to be very useful:

Tea tray:  Brewing puer with either a gaiwan or teapot can be a little bit messy and having a tea tray is a great way to contain the spills and drips.  No need to go huge and elaborate.  Just something small and easy to clean will do.

Strainer:  This is optional, but occasionally useful (I didn't use one for nearly the whole first year of brewing).  Having little bits of leaves floating in your cup isn't going to hurt you, but keep in mind those little bits will continue to steep in your teacup.  Still, I never noticed that my tea was too strong.  I do use a strainer now (only when needed since some teas keep themselves neatly in the gaiwan or teapot) simply because I want to feel as though I'm tasting the exact result of the steeping.  I've heard some say that using a strainer can contribute a metallic taste to the tea, but so far I haven't been able to detect that.

Serving vessel, or cha hai:  This is a little serving pitcher that acts as a holding vessel between teapot and cup.  You brew the tea in the teapot, you pour the tea into the cha hai, and then you pour the tea from the cha hai into the tea cups.  I use one when I'm having friends over for tea, or when my tea cup is too small to hold all the tea from the teapot.

Cha Dao utensil set (also called Gong Fu utensil set):  I dutifully picked up one of these when I first started drinking puer.  I fumbled around with the pieces for awhile and soon abandoned them.  It now sits unused in the back of a drawer.  But I know people who use them, so there ya go  :)

Puerh pick or knife:  If you start buying tea cakes, get one of these.  You'll be glad you did.  I've tried both a pick and a knife and much prefer the pick (I feel that knives tend to pulverize the leaves too much).

Presentation vessel, or cha he:  A useful little gadget, less so for presentation purposes than for getting large unwieldy dry tea leaves into the small opening of a teapot.  I still don't have one, and will pick one up soon enough.  For now I find myself creating makeshift cha he from tin foil when I'm wanting to really weigh/measure the leaves (which I don't do often) and transfer them into the pot.

Aroma cup set:  Two little cups, one tall and skinny (maybe 2 inches high) and one short and round, like this set here.  You fill the tall skinny cup with tea, then invert the (empty) short round one on top, like a lid.  Then you grab the whole contraption and turn it upside down so the short round cup is on the bottom and the tall skinny cup is inverted inside of it (with the tea inside).  Next, slowly pull up the tall cup, allowing the tea to fill the short round one.  Now take the empty (but still wet inside) tall cup, put your nose to the opening and sniff.  Notice how the fragrance evolves as the tea evaporates and dries.  mmmmm... a whole new level of tea wonderfulness  :)  A similar effect (the enjoyment of evaporative fragrances) can be had from holding the freshly emptied serving vessel under the nose, holding the pitcher nearly horizontal with the handle below (on the underside), the bottom of the pitcher facing away from you and the opening facing toward you.  Position the spout of the pitcher, which serves to direct and concentrate the fragrant vapors, just under your nose and breathe in the aromas (Michael Fung, proprietor of The Best Tea House in Canada taught me this).  You'll have to play a little with this at first to figure out just the right way, but your nose will guide you.  It's not hard to find the sweet spot.

Tea boat, water bowl, and other little goodies:  Never used 'em, can't comment on 'em.

How can I know which puers are good and which are bad?

Sample, sample, sample!  There is no substitute for getting out there and trying as many as you can.  Reputable vendors will offer sample sizes of their teas.  Still, the sheer number of puerhs offered at sites like Yunnan Sourcing (over 1000 at this writing) is truly bewildering.  Where to start?  Thankfully you'll find an abundance of tea bloggers who post their tasting notes and aren't shy to proclaim their preferences.  But keep in mind that just because Joe Blogger thinks a particular puer is the bee's knees doesn't mean you'll find the same merit in it.  Still, it can provide a starting point to help in picking samples initially.  After awhile you'll get a sense for what you prefer.

What should I look for in a puerh?

Finding enjoyment in puer tea is a case-by-case matter.  One man's bliss is another man's bitter brew.  The more experience you have with tasting different puers, the more you'll learn.  Try teas from different factories, mountains, blends, years, and "listen" to how you react to them (hence the name of this blog).  Try to ignore all the talk about aging potential, at least for now.  There are many opinions about what kinds of puers will age well (most coming from folks who've only been drinking the stuff a relatively few number of years).  It's the in-the-moment, regardless-of-age complexity and nuance of puerh that is it's allure.  Expect a learning curve as you start out and begin to develop your palate.

If you're just starting out, here are some of the things to notice while drinking puerh:

Taste:  What flavors do you detect?  How do these change from infusion to infusion?  Where in the mouth or throat do you detect various flavors and sensations?  Be watchful in the minutes after the sip.  Is there a sweetness that develops in the mouth or throat?  (see this post here for a discussion about hui gan)  Does any bitterness present turn to sweetness or other nuanced flavors around the edges?  Bitterness is not necessarily a bad thing.  There are different kinds of bitterness.  See if you can acquaint yourself with these and learn to discern them.  Another thing to watch for is what might be best described as "taste sensation."  After drinking a tea is your mouth or throat filled with a sensation of cleanliness?  Sometimes that sensation won't be so nice, like with this particular tea.

Fragrance:  Smell the leaves while they're dry, after the first wetting, and throughout the session.  Smell the fragrance from the tea liquid, and from the vapors that linger in the lid of the gaiwan or teapot after pouring an infusion.  Some puers will also give a fragrance (of sorts) in the minutes after you take a sip, perfuming the breath in the inhale and exhale (hui gan can also sometimes carry fragrance, see link in paragraph above).  For a little extra fun you might want to pick up an aroma cup set (see above).

As you make your way into the world of puerh you'll want to deepen and expand your awareness beyond the obvious taste and smell.  Following are some things to keep in mind:

Mouthfeel:  Pay attention to the feel of the tea liquid in your mouth.  Does it feel thick? Thin?  Does it feel dry or oily?  Does it coat the mouth in a pleasant way?

Clarity:  Observe the color and clarity of the tea liquid (or "tea soup" as it's sometimes referred to).  Initially this won't mean much to you, but as you gain experience with puerh you'll get a sense for how the color relates to the tea's age and processing.  A cloudy appearance to the tea liquid is generally considered undesirable and a sign of poor processing.

Bodyfeel:  You'll hear people talk about the qi of some puers, although there is sometimes debate as to what that means exactly.  Regardless of what can be suitably called "qi," you'll want to take notice of how the tea affects you both physiologically and mentally.  Yet another aspect of "listening" to the tea.  You might feel a warming sensation in the throat or abdomen... or the ears, or the top of the head, etc.  Some teas will quicken the heart, some will induce a sense of calm, some will seem to sharpen your focus while others will leave you feeling a little drunk ("teadrunk" as they say).  Each tea is different and will affect the body in various ways (or not at all, with some).  Your job is to simply to practice awareness and notice.  As with developing and refining your palate (your ability to detect subtleties and nuances in taste) and sense of smell, puer offers a great deal of wonderment in how it affects the body and mind, perhaps more so than any other kind of tea.

Appearance of the leaves, dry and wet:  Examine the dry leaves.  Notice the color, if they're brittle or flexible, long and ropey or short and piecemeal.  Are they shiny?  Dull?  Can you see leaves or buds, or is it just a mass of chopped leaf matter?  Are the inner and surface leaves of a cake similar or different?   It's also useful to observe the wet leaves, both throughout the session and especially at the end.  As with clarity and other matters, you won't quite know what leaf appearance means at first.  It's a learning tool initially, helping you to get better acquainted with the subtleties of puer.  Pick through the leaves at the end of your session.  What do you see, feel?  Are the leaves soft or do they retain a brittle quality?  Are the leaves tender and fragile?  Are they sturdy and thick?  Are the leaf veins prominent and strong?

More! More! More! I want to learn more!

There are some very good blogs, full of not only tasting notes but plenty of invaluable info and tidbits on the finer points of pu'erh appreciation.  A few standouts for the latter include MarshalN's blog, Teamaster's blog, and Mattcha's blog.  The Half-Dipper's blog is fun reading too, and while his blog places more emphasis on tasting notes it's sprinkled with plenty of tea wisdom as well.  Another blog of note is the Tea Urchin's blog, which is hands-down the most enjoyable tea-related reading on the web.  The author is an excellent writer with a knack for great story telling.

Another great online resource are the forums.  TeaChat is a large and very active one with a good search engine.  Other forums to check out include the Live Journal Puerh group and the TeaDrunk forum.  The Badger and Blade forums also contain some puerh-related threads that can be interesting to browse.

Finally, there's the online magazine, The Leaf.  A wonderful resource full of great information and beautiful imagery.  Very well done.  It can be hard to come by esoteric puerh knowledge written in English, but The Leaf does a great job of bridging that gap.

Speaking of magazines, you'll see The Art of Tea magazine for sale on a few tea vendor sites.  Like The Leaf, it's full of beauty and depth of knowledge.  Worthwhile reading if you don't mind spending the cash to pick up a copy.


  1. Dear LTPR,

    Its been a while since I've posted...

    Quick note on the production of Pu'er;

    The first stage you have marked as "drying" is actually withering, in tea production drying often refers to a heating process and is common in oolong and red tea to "finish them" by bringing the moister content below 7%.

    Not all Pu'er goes through sun-withering, though usually the better quality tea does. It can also be trough dried (placed in a trough with air running under it), shade dried (uncommon for Pu'er), or even placed by a fire (this is common if it starts to rain during the withering stage and does not yield good pu'er).

    At this point the tea is MaoCha, which means more literally "raw tea" than Sheng does.
    MaoCha is Pu'er that has not yet been "infected" by a microbial colony; thus it does not age.
    (Some people will disagree with that, but it does not age the way Pu’er does as there is no fermentation)

    At this point, all MaoCha is left to age anywhere from a few weeks to 5 years. This ageing is not included in the age of a cake. In the past, longer ageing was common, but with the demand for tea in the more famous regions, MaoCha ageing time has decreased.

    For Sheng Pu'er, MaoCha is aged on straw mats (better) or cement, and is infected with the microbial colonies (not simply mold) that give each factory its unique flavor.

    Shu Pu'er goes through this same process,
    but on a heated platform. Water is added to the tea as it is being heated giving the microbes a nice warm and moist place to grow. The pile is turned every once in a while. This process selects for very different microbial strains, thus the same MaoCha produced as a Sheng and a Shu will not taste the same.
    Shu pu’er was invented in 1972 by Kunming Tea Factory while experimenting with ways to artificially accelerate the ageing of pu’er. Its first commercial production was 1976.

    At this point the Pu’er is fermenting. That means that a group of microbes (yeast, mold, and other bacteria) are consuming the tea and excreting something new. Because tea is more complicated than fruit juice, and because Pu’er has mixed colonies, we get something more than sugar into alcohol.
    (I do an entire lecture on tea chemistry)

    After the MaoCha is aged the tea is steamed and pressed into whatever shape the factory wants, then the tea is left to loose moisture for about 3 months. If the tea is steamed at too high of a tempter, the microbes will die and the tea will suck.

    Now the real ageing begins. Because of the compression and reduction of oxygen, the tea begins to ferment at an accelerating rate. Ageing is all about keeping the microbes happy, which requires a dark and slightly moist environment. There is a lot of debate about the right humidity, temperature; The Institute keep the RH at 65% +/- 15%, and 700F +/- 100.

    Both raw and ripe Pu’er can be consumed as soon as it has been compressed (though I suggest waiting at least the 3 months it needs to loose moisture). Continued ageing should, in good pu’er, increase complexity and decrease bitterness.

    Hope this helps!

    We have the Korean Tea Exhibition,
    at Penn State University from April 4th - 7th.

    Shoot me an email at jmc5840 [at] psu [dot] edu
    if you would like some more info!

    All the Best,
    Jason M. Cohen
    - Director of The Tea Institute at Penn State

    1. Dear Jason,

      There are some problems with your comments here that need some clarification, and some internal contradictions that don't seem to resolve themselves.

      1) Maocha that never made it into cakes most definitely does age. If you haven't tried aged maocha, you should, because that stuff does change over time. Or, maybe I along with a whole bunch of tea drinkers are all imagining things.

      2) To call puerh aging "fermentation" is itself somewhat misleading, as sheng puerh, without going through traditional storage, doesn't necessarily have any fermentation going on (by fermentation we generally mean the conversion of some types of raw materials, most often sugars, into things like alcohol and others through the agency of yeast, mold, or bacteria). Those teas, nevertheless, age. In fact, my vacuum sealed bag of oolong ages over time too, and calling that "fermentation" would be a real stretch for the definition of that word.

      3) Since you claim that maocha does not age, then what is the point of "aging" said maocha from a few weeks to five years before pressing? If they only start to age when they pick up bacteria and other microbial agents on the straw mats or concrete floors, as you suggest, then do you mean to say that all the other surfaces they came into contact with, up until this point, are bacteria free? Surely you don't mean that, do you?

      4) Do you suggest that for up to a few years the maocha sit on the flat surface of the factory, all laid out?

      5) I'd contend that the unique flavour of each factory, insofar as their sheng puerh is concerned, has far more to do with a) where they source their teas from and b) their blending and c) their processing (kill green, etc) rather than whatever bacteria they pick up while there. With regards to shu, the particular strain of bacteria they possess and the techniques they use in maintaining and turning their tea piles are far more important than any type of aging of maocha that actually happens.

      6) Heat is generated internally for the processing of shu puerh and does NOT require an external heat source, so long as you have a big enough pile and the right conditions (water, etc). Of course, it is possible that some engage in such activities such as adding heat, but traditional shu puerh processing does not involve any additional heating - the composting process will take care of the heat on its own, reading internal temperatures of 150F or more. When they turn the shu pu piles they tend to be steamy affairs, through no added heat.

      7) You say "the tea is left to loose (sic) moisture for about 3 months" after the pressing of the cakes. May I ask how is it possible for vendors to start selling current year spring tea in mid April then? Are you saying they're all doing it wrong? Some will, perhaps, indeed leave cakes around for a few months, but as far as I am aware, mere weeks is sufficient in drying the cakes (days can be a little risky, depending on drying conditions)

      8) Just adding up the times you claimed are necessary, we're talking about 5 weeks minimum for maocha aging, plus three months of drying, so the earliest a new, spring tea picked in late March can show up on a reputable vendor's shelves is probably somewhere in mid August? That seems to fly in the face of all evidence, from major players in the market such as Dayi to the smallest independent producer, many of whom are very serious tea people who seem to know what they're doing.

      9) "The Institute keep the RH at 65% +/- 15%, and 700F +/- 100". Wow. Your tea is very, very hot, and pretty dry. How do you keep it from burning up?



    2. Dear LTPR and MarshalN,

      Allow me to clarify;

      1&2) The difference between loose Pu’er and MaoCha is the inoculation of microbial colonies. Pu’er has been inoculated, while MaoCha has not. MaoCha ageing is an oxidative reaction mediated by localized bacteria (and possibly yeast) present on the surface of the leaf. The bacteria does not begin fermentation as fermentation is an anaerobic (no or reduced oxygen) process. Thus MaoCha and Oolong do age, just not in the same way or process as post-fermentation teas such as Pu’er. Oolong can age through oxidation in a sealed bag as there is oxygen present… even vacuum sealed bags are not complete vacuums and still contain oxygen. This oxidative process is slowed, which is why people bother with sealed bags in the first place. Oolong will not age in a nitrogen flushed vacuum bag (I have no idea what the long term storage effects are, though I’d guess this should only be used for short term).
      Both Sheng and Shu Pu’er go through fermentation. If the cultures in your Pu’er have died, something has gone wrong. We believe the primary fermenting agent is a subspecies of L. Bacillus, and we know much of the unique flavors from regions and factories are from isolated local strains of yeast present on the surface of the leaf during processing. This fermentation is similar to the fermentation in beer, wine and cheese, which produces quite a bit more than simply alcohol; that is why artisan beer producers use specialized yeast strain, why champagne yeast produces smaller bubbles, and cheese caves (for blue cheese) have their own self promulgating culture.

      3) The ageing of MaoCha that I referred to is the inoculation phase, and some oxidative ageing also occurs in this phase. Often during this phase tea from other regions is blended, adding new yeast strains; this does not begin fermentation as, again, fermentation is an anaerobic process. Furthermore, just because bacteria are present doesn’t mean you can taste it. There are bacteria present on forks and bowls and surly you don’t claim to taste the difference between your fork and another (and if you did, you would probably request a new fork!).

      4) No, for shorter ageing durations the tea is in piles. For longer storage the tea is often packed into sacks of the same material that the tea is pressed in. I believe the material is burlap, though I’m sure certain factories use other textiles.

      5) For Sheng, source, blending, and processing are all what give a certain Pu’er its unique qualities… what else is there? I would like to remind you though, that the source and blending are what give and add unique strains of yeast to Pu’er, which gives the tea its ageing potential and is responsible for its future flavor profile. Many of the strains are present on the surface of the leaf and survive processing, I conjecture that most of the bacterial fermenting agents (non-yeast) come from the straw mats that are cycled through at the factories (new straw is added when the current straw run low) and become self promulgating. Should the yeast die, the only ageing that will be going on is the oxidative type (which is very sub-optimal in my opinion, and why the Institute never shrink wraps our Pu’er to halt ageing).
      For Shu Pu’er, I agree with you.

      [Continued in next comment, ran out of space]

    3. 6) You are right; no external heat source is required. That said, Shu pu’er should never be allowed to heat itself to 150F as you said; yeast and most other fermenting agents die at 130 – 140F. Some larger factories do use heated platforms, though I believe this produces inferior shu.

      7) Vendors can do what they want. Pu’er, depending on the relative humidity will lose quite a bit of moisture for about 3 months after steaming. We have tested this at the Institute.
      On a side note and anecdotally, I wonder if many early tea reviews are negatively (or positively) impacted by this… I think there have been many times bloggers have reviewed a “fresh” tea and disliked it only to come back to it some months later and enjoy it… [I don’t have any data on this].

      8) As I said before, many groups traditionally (rare-ish) or recently now age their MaoCha for shorter times. Just because tea is being sold, doesn’t mean it’s ready for drinking; you don’t steam your tea Lu Yu style do you? The tea will continue to lose moisture at any lower RH, and Pu’er is supposed to aged, remember?

      9) We use a thermal shield made of silver impregnated silica adhered to a tungsten-carbon tube alloy, and we get excellent results.
      Thanks for spotting the typo, it should be 70F.

      All the Best,
      Jason M. Cohen

    4. Judging from your reply then, it seems as though you have identified the yeast strain for the aging of puerh as a subspecies of L. Bacillus. I don't think such a strain exists, unless you mean Lactobacillus, which is not a type of yeast at all.

      Care to tell us where exactly this yeast strain can be identified?

      You say "we know much of the unique flavors from regions and factories are from isolated local strains of yeast present on the surface of the leaf during processing." Your "yeasts" are awfully specific in where they hang out, and by that logic, once you move the tea to somewhere else, the local strain will infect and possibly takeover. Then all of a sudden it's not about where the tea was made, but where it's stored.

      If all the yeasts die at 130-140F, as you claim, then clearly during steaming they also die off, at least what was on the tea until that point, unless you think there's some mysterious process where they don't die because of steam, which comes in a lot hotter than 140F. So, again, it matters more where you send the tea onwards from that point forward, rather than what was on the leaves up until then. By your logic, where "yeast strains" impart local flavours, then all the teas stored in the same place ought to have the same taste. That is clearly not the case, as anyone with any tea drinking experience can tell you. Your version of the story doesn't make sense at all.

      The idea that maocha is aged is a mere speculation among some people, and has hardly been proven as a definitive method. Some factories, especially the state owned ones, certainly had some teas that they stored unpressed, but that often had more to do with political realities and inefficiencies in the production process than a willful aging of maocha.

    5. Dear LTPR,

      I'm sorry this debate has taken on a less than civil tone on your blog.

      Dear MarshalN,

      I never claimed Lactobacillus was a strain of yeast, I wrote that it was the primary fermenting agent. That is why I referred to microbial colonies which include yeast, bacteria, and mold.

      Lactobacillus is a huge genus of bacteria that uses the lactic acid bio-pathway for respiration. Knowing the genus is not incredibly useful as each species, subspecies, and strain will metabolize different compounds from the leaf into different flavor and non-flavor compounds giving each tea infected with each individual strain and combination of strains a unique flavor profile. The same holds for yeast.

      Wild yeast is present nearly everywhere, not only on the surface of the tea leafs destined for your Pu’er cake. But who cares if the tree bark has a unique strain of yeast? The tree bark isn’t processed into tea, and isn’t aged through fermentation.

      You are right that some strains of microbial colonies are dominant. That is why mold in a Pu’er closet can be dangerous; it can spread like wild fire and potentially ruin your tea! [Some strains of mold are fine and beneficial to Pu’er]. That said, not all strains are dominant. Some strains are localized or semi localized to the tea that it has infected, and most of the time no single strain is dominant. Furthermore, where a tea, especially Pu’er, is stored is very important to it flavor profile. We are not sure how common cross colonization of yeast is, but we do know the more tea in a storage unit, the better the ageing, and the better the RH regulation; we know that has something to do with cell respiration, and it’s certainly not the tea as those leafs are dead.

      The provenance of tea does make a difference to its flavor. I never said otherwise.

      Yeast dies at 140F ( That doesn’t mean the colony dies instantly, as they have some resistance. This resistance can be modeled by the Thermal Death Curve (redacted to get around spam filter, just wiki it). I don’t know what processing of Pu’er you have seen, but I have never seen or heard of a producer shoving their Pu’er into a steam pipe… People sit in saunas and steam rooms all the time and aren’t boiled to death. This is because steam is actually cooler than boiling water do to the latent heat of vaporization (an endothermic reaction), the surrounding ambient temperature reduces the total heat, and because the Pu’er is steamed inside one of those burlap sacks I mentioned in my first post. All of this reduces the heat so that the amount of time the Pu’er spends in the steam is less than the thermal death time of the yeast. (Unless, like a mentioned in my first post, they make a mistake and kill the yeast; then the tea will suck).

      Here are 3 examples of aged MaoCha, for both Sheng and Shu by people who know what they’re doing…
      [2 examples redacted to get around spam filter]

      I would like to close this debate with the statement that I don’t believe I or anyone else knows everything about tea. There is no one right way to drink, brew, or process tea, and there are infinite variations in the methods that are practiced. The Tea Institute exists to teach and preserve all tea ceremony, not just Chinese, and to allow structured undergraduate research in topics pertaining to tea. We help students, community members, and other individuals both online and here at Penn State understand the science behind tea and find their path in the tea world.

      I sincerely hope you keep posting on your blog and finding your path through tea, even if we have disagreements from time to time.
      We are all still learning mate…

      All the Best,
      Jason M. Cohen

    6. Dear Jason,

      "I would like to close this debate with the statement that I don't believe I or anyone else knows everything about tea."

      If you said this from the outset, we could've saved a lot of time. Your initial post is written with the certainty of someone who knows everything there is to know, except, as I've already pointed out, there are plenty of issues with your original post as written. The problem is of course nobody knows everything about tea, and to claim that there's one truth to it all (such as suggesting one optimal process of aging tea, as you outlined the process yourself - and then suggesting those who do otherwise are just wrong) is grossly misleading. The tea world is wide and varied, and there are all manners of innovation and changes that are happening, many of which will no doubt violate your idea of what's right. I'm glad you acknowledge it now.

      "The provenance of tea does make a difference to its flavor. I never said otherwise."

      Please see the following quote from yourself: "For Sheng Pu'er, MaoCha is aged on straw mats (better) or cement, and is infected with the microbial colonies (not simply mold) that give each factory its unique flavor."

      Written as A does X to B, which leads to C. The logical link is that C is caused by X, which is performed by A, which in this case is the "infection" of "microbial colonies" that "give each factory its unique flavor". By the way you described, the only thing that gives these teas their unique factory flavour is the microbial colonies. Never mind blending, other processes, or the origins of the teas themselves, which also greatly contribute to each factory's unique taste profile. If it's only one of the many factors, then you should say so, because we can't read your mind. I'll even say that it's a very tangential factor - that other processes and leaf origins are much more important, but that's a different point entirely.

      As for Hailang's cake that you linked to on YSLLC - the same person who "knows what they're doing" also makes plenty of cakes (the vast majority of his stock, in fact) which are not aged for months before pressing. So he was either absent minded, momentarily sane, or just experimenting with different methods. I'm guessing the latter.

      With regards to the temperature, it's quite possible that the leaves themselves don't reach much beyond 140F during steaming, but I'm doubtful as to the survivability of any microbes on the surface of the tea during the process as there's likely to be a substantial difference between surface temperature and internal temperature. Again, your theory of the special microbes/yeast from the factory holding on for dear life throughout the aging life of a cake just doesn't hold up.

      I am not saying there's absolutely no truth to the possibility of some microbial action affecting how a tea tastes as it ages, but I think you should rethink the entire process of how it happens and what other possibilities there are instead of just sticking to your guns.

  2. Jason,
    Thank you so much! What a treat to have you explain this. I've learned much and would like to make a note in the post above for folks to refer to your comment here. I appreciate your knowledge and willingness to share it :) Again, thank you!

  3. Oh, a question for you Jason -- when you say "For Sheng Pu'er, MaoCha is aged on straw mats (better) or cement, and is infected with the microbial colonies," do you mean that the MaoCha is actually inoculated purposefully with specific microbes, much like cheese is inoculated with specific microbes? I had thought the process was a little more natural and 'left to nature' than that. But maybe I'm misinterpreting your meaning? (this discussion is fascinating, by the way!)

  4. The one from hojo is a very lovely, simple and clear illustration!

  5. MarshallN -- always a pleasure to be treated to your great insights. Thank you so much :)

    Gingko -- Yes, I thought that was an excellent explanatory image for someone who's new to pu'erh!

  6. we plan to have a 2012 darjeeling first flush online tea tasting session .. any ideas on how we can work on it and have more and more people participate so we can make people aware of single estate high end darjeeling rare exclusive teas ... also more and more discussions would help us interact with each other ... thank you! ankit lochan -

  7. I have been unable to post my reply since yesterday. I believe the comment was flagged as spam because of the number of reference links...
    Not sure whats going on. I will try to have my response posted soon.

    All the Best,

  8. As much as I enjoy a good intellectual brawl, I think Marshaln and Jason have scared off the kids! Fascinating debate though! Thanks for your gentle & comprehensive layman's intro to the fetishistic world of puer Bev. I appreciate the kind words & link love! Drop me an email with your address so I can send you little bits of Yunnan sunshine.

  9. Dear All,

    Sorry my reply took so long to post.

    I contacted google and the short of it was "delete some links!" to get around the spam filter.

    All the Best,

  10. Everything Jason has said is consistent with what I've learned about puerh as a biologist and a long-time tea enthusiast (and I learned some new details as well!). Thanks for the enlightening debate.

  11. With much thanks to all who have contributed to this interesting discussion, I've decided to close the comments for this post so as to halt any further argument or taking of sides. It's been enlightening reading, in many different ways, and I'm thankful for those who have given their time and the best of their insights here. I'll end with a few notes from a wonderfully informative conversation I had recently with Michael Fung, proprietor of the Canadian branch of Best Tea House. His knowledge of puer is considerable, coming from decades of involvement at many different levels. I trust him implicitly, and respect him greatly. He read over my post and the resulting discussion with great interest. I asked him what he thought of the image I'd used from Hojo Tea, showing how shu and sheng puerh are processed. He felt it was accurate for the most part, including the part about the tea leaves being sun-dried for a short period. One step that was missing, according to Michael, was the withering of the leaves prior to pan frying. Also, he noted that the part about "fermentation by mold" for the processing of shu was not quite correct. A better phrase would be either "fermentation by wodui" or "fermentation by wet pile." Essentially, my understanding of the process after talking with Michael is this -- first the leaves are picked and then withered for a short time before pan-frying. After the pan-fry (which is very brief and done at a lower temperature than, say, for green tea) the leaves are then rolled and twisted, and then set out to dry in the sun for about 5 to 8 hours (sometimes less, sometimes more). At this point the tea is called maocha and is ready for the remainder of the process (either being stored for a time or processed for either shu or sheng puer). Although different factories may have somewhat different approaches, this is essentially the process and is not a hugely difficult of complicated one. Michael also pointed out that the processing of shu puer does not involve setting the leaves on a heated platform. Rather, the leaves are piled onto a cement floor, wetted with water and then covered with mats. Heat is generated naturally within the pile bringing about the fermentation that is part of the process of making shu puer.

    Thanks again for an informative discussion :)