When someone mentions humidity in tea discussions (mostly related to storage of pu’erh, of course) they always seem to use relative humidity (a percentage of how much moisture the air can contain at a certain temperature and air pressure, as I understand it). I consistently see people refer to humidity as a simple percentage but as far as I can remember I never saw anyone talk absolute humidity (kg/m3).

Let me give you an example:
Here in Stockholm right now the relative humidity is 80% at 7 degrees C and 998 mm Hg pressure. That makes the absolute humidity 0.006 kg/m3.
In Hong Kong today the relative humidity is “only” 73% but at 24 degrees C and 1014 mm Hg pressure which works out to an absolute humidity of 0.016 kg/m3.
I used an online calculator to get these values.

So if I was comparing humidity with someone in HK using only relative values it would seem like my tea is stored “wetter” than his, while in actuality his tea is stored at almost three times the humidity mine is.

My thought here is: should we not be talking about absolute humidity instead? Surely what affects the tea must be the absolute amount of water in the air, not relative humidity?

Please educate me if I am missing something here.

Humidity, relative and absolute (pu'erh storage)

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