About boiling wood

I boiled some maple today to make it easier to carve.  I just used a saucepan and only had the heads of the spoons in the water.  I boiled them for about an hour and a half - boiling for 50 minutes or so and then simmering for the rest of the time.  It worked well.  The stuff was much easier to carve.  Easier than when I soaked it, and much faster.

When you boil maple, you get water that looks like this:

This makes me wonder.  What exactly is that boiling doing to the wood?  Is that just a bunch of tannin in the water?  And am I hurting the wood by removing that tannin?  I sure hope not.