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Hi! Fairly new to cider and loving it. I've purchased a used corny keg and some other parts from a guy locally. While I was there to pick it up he realized he'd left a kiwi beer in the keg (I don't know how long). There was a thick brown film on inside when I got the keg that didn't come off...

I'm fairly new at home brewing, and just made my first attempt at Hard Seltzer (raspberry). Tried it for the first time, tasted good, looked clear, smells like seafood (or something similar). My only thought was I used one of those two-stage packets for clarifying, and believe at least one...