Brewed a beer a little while ago that fermented like crazy (pitching to FG in about 3 days or so). Got wrapped in stuff IRL, and had to leave the brew inside the primary for longer than normal... Somewhere like 4-5 weeks total. Since it fermented so quickly (to over 10% abv nonetheless), I had decided to let it sit for a bit longer anyways, to make sure it aged better and didn't get too much boozey heat.
Well I transferred to a secondary a few nights ago, just so it wasn't sitting on the trub any more. When I popped the fermenter top, it had a really distinct acetaldehyde smell (resembled a cidery smell). I took a sample for tasting, and I don't taste anything crazy, it actually has sort of a bland taste to me but oh well.
I know acetaldehyde is necessary to create the ethanol, and I know in the past I have merely had to wait it out and eventually the smell disappeared. My question is... Has anyone ever had a brew where an acetaldehyde smell did not disappear? Besides being "green", I don't know of a reason why such an off-flavor would develop, and I'm pretty confident in my cleaning methods. Any insights or feedback?