I knew something was wrong when I got home from a trip and saw that the blow-off bucket was empty. I had decided to cool the wort while I was gone, before I siphoned it to a keg. Unfortunately, I forgot one of the 1st laws of thermodynamics........ things contract when cooled. When I pulled the carboy out of the fermenter and was ready to siphon, I noticed a clear layer on top of the Alt. After letting out a cacophony of four letter expletives, it all made sense. The drop in temperature in the carboy sucked all of the starsan and blow-off goop back into the beer.
My beautiful DDorf Alt that I thought was as tasty as anything I had made had been violated!
I very slowly siphoned the bottom layer of beer out from under the clear top layer. It appeared that it did not get significantly disturbed. No obvious off flavors. Maybe a bit watery. The FG is now 1010 - it was 1012 before I left. It is now getting force carbonated. I guess we will see what happens.
Moral of the story - I should be reading more of the forum and its wealth of info, and learn from the experiences of others (I would lay money that this topic has been discussed before), and not just the things that catch my attention.
And get rid of the blow-off tube before I chill.