Is my beer oxidized?

Question

I brewed a batch of bitter 5 weeks ago, simple recipe with 90 % pale malt and 10 % crystal. IBU is aout 30. I have brewed this beer before, and it was great.

Everything went perfect, up until I pitched yeast. It is a long story: re-pitched yeast harvested from primary from earlier batch (WLP002), but I pitched way too little. The fermentation did not start within 48 hours, so I repitched fresh yeast. That is to say, the wort was aerated 48 hours before the "real yeast" was pitched.

The fermentation then proceeded as normal.

4 weeks later, properly carbonated and all, the beer tastes bad, or "not that great". Definitely not infected. It is a strong yeasty taste (the beer is clear), with sawdust like notes, and the bitterness is very pronounced. All notes from caramel malt etc are gone. But to call it "wet cardboard" is a stretch, but then again, I have never tasted that.

Is my beer oxidized?

Edit: I have noticed that the bottles have all small bubbles on the inside of the glass. Some bottles have a very, very thin film of something oily in the air/beer interface. Could it be a beginning infection?

Answer 1

Certainly doesn't sound like it. Oxidation can take a number of forms other than "wet cardboard". It can manifest as metallic flavors or weirdly caramel notes. It sounds more like an infection than oxidation to me.

Answer 2

From experience, and I've had a few that have defied all odds, if you take just the very basic measures to prevent oxidation in your beer (e.g. syphon it, don't pour it), it is more often than not difficult to oxidize it enough to taste it. I've siphoned beer with plenty of bubbles visible in the hose, I'm about as graceful as a coked out beached whale when it comes to moving carboys around or a freshly filled keg (no CO₂ yet) to the keezer for forced carbonation, and I've even ice-condensed a barley wine which included the step of dripping off the condensed beer into a jug a foot or two below the massive ice cube, I don't think I've ever tasted the effects of oxidation, or maybe I have and just didn't know it.

Long story short, unless you did something that caused you to cringe and leave little doubt that the end product is oxidized (at which point, you're probably going to psych yourself into tasting oxidation, even if there isn't any, just to verify your pessimism), it's probably not.