Beer left in the fridge for a long time, now it tastes... horrible!

So, my first brewed batch was an Extract Alaskan Amber clone. It was fruity and not real good to be honest. But, my boss freaking loved the stuff. So I gave him my last six pack and he stuck it in the fridge at work and we forgot about it.

Fast forward 2 months. We were downstairs playing ping pong last Friday and I found 4 of them, pulled one out and cracked it open. Now, I really, really like Amber beers. And this one was overly sweet to me to begin with. But now... oh my gawd. It tasted like carbonated, spoiled orange juice almost. It was disgusting! WTF could have happened to it while sitting in the fridge, in a sealed bottle!?

maybe bad bottle sanitation.

bad bottle sanitation

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That's almost certainly the culprit. You state that it is still carbonated, so it's not oxidation from having slow leaks or anything like that. At fridge temps, the processes that condition/spoil beer creep to a slow crawl, so a good beer isn't going to just turn into a bad beer in 2 months at fridge temps UNLESS you already had bacteria of some kind in the batch/bottle in the first place.

Sounds like poor bottle sanitation to me. If you're getting a musty/cardboard-like flavor that would be oxidation. Sounds like it wasn't great to begin with so it's not a terrible loss.