Kegging vs. Bottle Conditioning

Having bottle conditioned my beers for the past 5 years, I just started kegging with forced carbonation.  None of the forced carbonated beers have tasted anywhere as good as my bottle conditioned beers; they all have a dull flavor.  The bottle coditioned beers tend to be clearer, brighter and much more focused in flavors.  The difference is less striking with dark beers or very hoppy beers. I recently split a Helles batch between bottle conditioned and forced carbonation, and the results weren't even close! The bottle conditoned beer was so much more focused.   Are there differences in CO2 sources?  Are some commericial supplies of CO2 dirtier than others? How about keg conditioning?

Any thoughts?
Richard

I assume, since you split a batch, that the bottled and force carbonated beer is the same age -- they went through the same basic fermentation, secondary, and conditioning periods? Could the difference be one of carbonation level? If the kegged beer is more or less carbonated than the bottled beer, that will affect flavor a lot. Another possibility is the temperature at serving, and possibly the amount of time spent at serving temps. It takes some time for the CO2 is properly dissolve into beer, and that's often a complaint that keggers have. I'm not really sure that helps you, but just a couple things off the top of my brain.

You asked about naturally carbonating in the keg -- that's what I routinely do. Immediately after primary (which in the case of most beers I do is 5-7 days), I transfer to a corny with a little more than 2 oz of candi sugar and let it naturally carbonated (like cask conditioning). I'm very happy with that method, but success really depends on the yeast strain you use, especially the flocculation and how quickly the yeast works. Belgian yeast is the hardest to deal with -- the couple times I've used that, I've ended up with vastly overcarbonated beers. Again, just a couple things for you to think about.

Do you also use an elevated CO2 pressure to finish the carbonation or just the kick from the natural process?

Preston