NO! I did not steam a pu erh cake.
Look at the enclosed information and instructions that came with this 2006 Mengku cake (click pix 2 for enlarged view). The instructions to break up the cake was "Shell the tea biscuit first, steam and knead it in loose state ready for use". This "steam" instructions were clear and not a mis-translation from Chinese to English.
So is 'steaming' to break up a tea cake correct? The instructions did came from a renowned tea factory. I asked many pu erh tea drinking friends in Singapore, Malaysia, Hong Kong, Taiwan and Guangzhou. This is what I found out.
You do not break up a pu erh tea cake by steaming the tea cake.
All my tea drinking friends and proprietors of tea shops I know do not steam their pu erh cakes. This is what I surmised after talking to them about this steaming method - Adding moisture deliberately to a tea cake by steaming is not good. This excessive moisture will affect and 'spoil' the tea leaves and would make brewing tea with these leaves unpleasant. Moreover, if this steamed tea are not drunk and kept in a tea caddy, the tea may turn moldy due to the higher moisture content in the tea leaves.
You will not see this 'steaming' instructions in newer cakes.
Old traditional Hong Kong storage of pu erh cakes are different. Here the tea is stored in warehouses that are slightly more humid. The storage time of the tea are controlled and checked..... and are taken out of the warehouses when the desired level of storage is achieved, about 6 months to a year (I will verify this again).
I break open a tea cake with just my hands if possible. If the compression of a tea cake is high, I would use a metal letter opener or a pu erh pick (resembles a mini ice pick) and gently pry open the cake into smaller pieces so I can loosen up the tea leaves.
Anyway, back to this cake. I had enjoyed this cake and I am happy I had purchased a few of these cakes when I had visited Guangzhou back in 2009. I normally use 8g to a 180-200g teapot but for this tea, I add 2g extra to make a brew. This enhances the strong chinese herb aroma. I particularly like this comforting tea and would brew it just before my bed time.