This is a great question. As some of you have already pointed out, as a shengcha pu’er comes into contact with the elements and begin to go through slowly the process of post-fermentation, it gradually turns into a dark tea, in the same category as shu cha pu’er. As to at which point it is a dark tea, initially I have wanted to work with scientists or perhaps if there are already existing datas, to come up with a definition. However, I do have some other things to ponder about too and would like to give a definition that covers a few perspectives. 

Do remember that though, the post-fermentation process with which each batch of shengcha — be it in compressed forms or loose leaves — transforms, is very likely to differ dramatically to another. This, plus the different nature of the original leaves, is going to yield extremely varied final chemistry of the tealeaves. 

The Taiwan study which datas I have quoted in this article: https://www.teaguardian.com/tea-health/puer-health-sheng-cha-or-shu-cha-1.html, reflects only a small fraction of the huge variety of products labelled as pu’er in the market. However, it does give a general idea as to the gradual change of chemistry as the tea slowly darkens.

It would be a bit irresponsible not to give a temporary solid answer to Sophie’s question, so I’ll say from a user’s point of view in judging whether a shengcha is TCM a bit milder. Not by the leaf colour, esp when it’s a compressed form. The infusion colour is a bit more reliable. Do a 3g to 150 ml 5-minute infusion test. The taste should be sweet, the colour should be very dark with refractions showing colours from deep brown to deep red. This is of course for tasting test; you can adjust the concentration in daily consumption.

@Ctran, fresh college grads are too green to do anything, esp in China where ppl are not taught independent thinking in education. They are good to follow simple orders only. Ppl who are serious enough to go to grad school in tea are either very focus in specific area or too well connected to be faithful to you, more so when you are working with them remotely. There are also those who are not too honest. I don’t blame them though; in a society where corruption prevails and money and power are justice, morality is but a hermit. In another word, it’s not easy to find a good partner or employee. Like Manila, I paid my dues too.

…aiming at the mass market may not be the quality you want to achieve. Having said that though, that is not to say there are not good people there, however rare they are.

@Ctran, this is a most admirable ambition. It is not an easy one to achieve though. I have been buying from smaller producers since the beginning of my tea career and there are many aspects that need great efforts in, unless you do not mind bad quality hurting your name, or losing money to various bad practices by the very people whom you want to support.

@Chawang you are definitely hitting the core of the issue: differences in the people. 

Most often people easily collectively think of smaller farmers are one kind of suppliers. They are not. They are as varied as personalities, i.e. there are honest, skilled, and good practice people of various backgrounds and limitations, there are also opportunists, shady people some of whom can pretend very well to be, say, high quality traditional tea producers. Whichever group one may belong to, he can be successful, mediocre or a complete failure. Not any different from any other trade in your part of the world, or mine.

In order to contribute to the promotion of small, independent farms, there are a few things that I do and, so far, they have worked for my business:

• Find real quality, consistent producers
• Find at least two for each type of tea you’ll carry
• Establish a personal relationship with them, ie, do care for them as individuals. It is love to other people that you do such business afterall, right?
• Understand that they have great limitations as normal suppliers, and which are they in terms of possibilities of limitation and hinderance of your own business operations
• Devise ways that you can do to compensate for these limitations. If such devise is not possible with any particular one potential, don’t commence working with him yet.
• Understand the quality and market price of similar products available through larger producers. Weight the difference in the small farm and quality marketing pretext

These are the parts concerning the supply side. Operation, marketing, management, and business strategies are other things you’ll have to be good at in trying to gain a foothold in the competitive tea trade. 

And then there is the basic necessity of knowing your products. This not only for selling, but in day one when you approach potential suppliers. They are human afterall — they have all the weaknesses of any human and can easily fall for temptations of cheating, despise, and most often, lost of faith.

Clay kyusu has a long history in Japan for making green tea in. Indeed, when Yixing teapot began to take its place as the de facto teaware for connoisseurs, the overwhelming majority of tea in the market was green. Poems and literature have presented them as pairs since the 17th century.