The greatest bike skill ever.

[LPC2104]

I was thinking wet cardboard, but cigarette butt works too.

While I doubt the Mr Beer kits are good, it sounds like this was a problem with the brewer, not the brewkit.  A "wet cardboard" taste  is a common product of oxidation.  Be careful when racking. 

That said, Bargovic knows my views on light beer. 

That's what I figured out later, but that only accounts for the wet cardboard taste.  It was a bad recipe anyway.  It was just powdered malt extract and dextrose.  No whole grain at all.  It would have been bad even without the oxidation. 

Oh, and it hit me the other day as to the most likely reason why my most recent batch didn't ferment correctly.  I failed to rinse the bottles with clean water after sterilization so they had a small amount of bleach in them. 

P.S.  Careless racking results in bacterial contamination, not oxidation.

I agree the beer would probably suck with those kits.

Not trying to be picky but you really shouldn't use bleach for cleaning anything that you are going to use beer with.  Use iodopher for sterilization, it's really cheap and it last a really long time.  2 capfuls per 5 gallons.

P.S. Careless racking does result in oxidation, along with infections.  No splashing allowed.