Too Much Decanter Time?

We've gotten into the habit of decanting most of our red wines over the past year, or so. While the results are certainly not scientific my experience has been that more time in the decanter seems to equal smoother, more open wine. That's up to eight hours and beyond. Most of the wines that we drink are relatively young, 2000 vintage and newer. The rule of thumb seems to apply to Pinots, Cabs, Zins, Tuscans, clarets, etc. Have others had the same experience? Within reason, is it possible to over decant a young wine?

[David M. Bueker]

I think you can over-decant young Bordeaux to the point where it clams up. I also prefer to allow Burgundy to evolve in the glass rather than in a decanter (don't want to miss a thing...).

David,

I need to decant and sample a Bordeaux over an extended period (24 hours) to see if it gets to the "clam up" stage. The young ones that I have been drinking still seem to be going strong after ten hours.

We usually decant older Burgundy just before consuming. The younger ones do seem to benefit from 2-4 hours in the decanter. Even after these several years of drinking Burgundy it remains largely a mystery to me.