puerhking wrote:now that i have tried a few stone pressed pu's it seems to me that they are much more mild...and therefore more approachable. is this because i can get more whole leaves or is there more to this mystery? do tell.
I haven't found much correlation between compression and mildness or approachability. But, Hop's point about the "wholeness" of the leaf stands true. Broken leaves = stronger flavor.
hop_goblin wrote:
<snip>Tie beengs or "Iron pressed" compress them to holy beat hell. This does not facilitate aging very effeciently meaning it takes longer for the air and humidity to do their magic. <snip>
There are actually 3 types of compression: stone-pressed, hydraulic-pressed, and hyrdaulic pressed molded tea, or tie bing.
Tie bing refers to a particular kind of high compression
molded cake that has flat edges and hobnails. Most hydraulic pressed teas are not as highly compressed as
tie bing and nearly all take on the traditional
qi zi shape. Probably over 95% of all non-Xiaguan cakes are hydraulic pressed
qi zi cakes.
Also, many companies claim to stone press their tea but do not. They just steam it longer and hydraulic press it to a lower compression.
Stronger compression became valued because not only was it faster and more economical, but it also kept the pu'er cake more intact over time. Aging in humid environments loosens leaves from the cake. For example, famous antique cakes like Tongqing and Tongxing of the 1920s-40s now weigh only 300-320g, sometimes less; some 30g-57g of tea was lost over time because of the loosening of the leaves. 1950s-1970s guang yun gong bing, which were
tie bing, have not lost nearly as much leaf, and probably won't. They're still very tightly compressed.
I've even seen my production of cakes loosen some in wet storage, and my cakes were somewhat tightly compressed with hydraulics. I've got some chunks of it in wet storage in a jar, and a good portion of leaves have already loosened, some 3% of it by weight.