I actually didn't know that, and just looked it up and you're right! I wasn't planning on collecting the liquid, but now after learning this, Im going to look more into it.
One thing I did notice the other day ( not knowing this) is how much liquid has separated from the pressed bean mixture. I did this once before ( a few years ago) and I dont remember as much liquid as I have this time.
I probably wont get to it until the weekend, but Ill start a thread and post pics of what I did and what I got now.