The purpose of this experiment is to observe the effect of humidity on shou puer.
The tea I used for this conditioning experiment is Yunnan Sourcing’s 2018 Serendipity. I enjoy this tea often and feel I have a solid understanding of how it should taste.
I separated several chunks of this tea from the cake, putting half of the chunks in one bag and the other half in another bag. To control the humidity, I used some silica desiccant packets and a 69% Boveda pack.
In the first bag of tea, I placed a few silica desiccant packets, then sealed it up. I checked the humidity reading every couple of hours with a calibrated analog hygrometer, until several hours later, the reading reached 50% RH. The silica desiccant packets worked surprisingly quickly. I removed the packets and sealed up this bag, deciding it would be better to let the tea rest a bit at its new humidity level before tasting. In the second bag, I simply let the 69% Boveda pack sit undisturbed during this period.
One week later, I confirmed that the first bag generated a relative humidity of 50%. The second bag read 70% RH. Upon comparing the samples in a taste test, I was unable to find a clear undeniable difference. However, this wasn’t enough to conclude that the moisture content of shou puer has no effect on its taste, so I decided to dry out the first sample even further.
I placed the silica desiccant packets in the first bag again, and dried out the tea all the way down to 25% RH. Again, I waited a week and verified the humidity reading before tasting. This time, I noticed that the drier (25% RH) sample was crackly and brittle while dry, but once again, in comparison to the 70% RH sample, I once again found no significant difference in taste.
To me, it seems fairly clear based on this experience as well as previous ones, that shou puer is not very sensitive when it comes to its moisture content. I’m not saying conclusively that there’s no difference, just that shou puer can still taste fine when very dry, unlike sheng puer which in many cases would be utterly undrinkable if it was dried out to ~50% RH or lower.