Saison sleeper off flavor

[TastyAdventure]

I brewed this saison in April 2016 (6 months ago) and it was great! But a couple of moths ago I started noticing a green apple type flavor in it. I thought this flavor only showed up in young beer?

Danstar Belle Saison Yeast, pitched at 71 and ramped up to 79 by 48 hrs after pitching.
Got up to 83 eventually.

I added a little citric acid for mash pH.

FG is actually 1.003
IBU is actually 24.5

Anyone know why I'm getting this off flavor? Don't want this to happen with my next saison

View attachment 373419

 

[MagicMatt]

Yes normally acetaldehyde is a precursor to alcohol. It is an intermediate compound that is formed prior to the formation of EtOH/ethanol during fermentation.

So acetaldehyde is formed as a normal part of fermentation...but then it becomes alcohol and is gone (hence in a well-fermented beer, you can't taste it). When EtOH is OXIDIZED, it will become acetaldehyde again, and then likely acetic acid, which is perceived as the cidery/sliced green apple flavor.

So it sounds like your beer got oxidized at some point in the past 6 months. How was it stored? Bottles or keg? Room temp or cold?

 

[TastyAdventure]

Room temp bottles. I haven't had an oxygenated homebrew in 3 years!

 

[MagicMatt]

I'm out of guesses then, sorry!

 

[TastyAdventure]

Anyone else have an idea?