First batch has refined to the flavor of..

.. wet cardboard. Oxidiation, I fear, but there's not a lot of talk on the subject. I kept reading about all of these off-flavors and wondered how in the world anyone would detect the flavor of wet cardboard. However, two weeks after bottling, I'm 95% sure that the taste is indeed wet cardboard.

So, what really causes oxidation? I know I made a lot of mistakes during my first time, but oxidation was never one of the concerns. Here are a few I made that may have contributed:

1. It took forever to cool my wort, and I was drunk, too. I think it took about an hour.
2. When transferring to primary to secondary, there was probably quite a bit of "spraying", since the tube was above the beer level for about half of the racking time.
3. I had to walk the secondary carboy upstairs and it certainly was moving/splashing.
4. I had to carry my bottling bucket from one room to the next, probably causing a bit more splashing.
5. I bottled the beer without a wand or tube. Straight from the spiggot into the bottle.

Are any of these mistakes major enough to contribute? Other mistakes I may have made?

I think out of all of it, the last one seems most likely to cause oxidation. Of course, any of those steps could have contributed, but I'm thinking that without a bottling wand, you got some activity in there that your beer didn't like.

Yeah, I think 2 and 5 are probably the biggest contributors. Get yourself a bottling wand and a longer length of vinyl racking tube and you should be in good shape.

1. Shouldn't be an issue.
2. Yeah, this will do it easily. In fact, this is probably the primary cause.
3. Not as big of a deal. The racking process should have caused the release of CO2 from solution so you had a blanket of CO2 over your beer by the time you moved it.
4. See #3
5. Yes, this will do it. However, I suspect #2 was the primary culprit.