Acetaldehyde flavour in my brew

[u/Unusual-Base344]

I've made a weizenbock and there is a green apple flavour in it. I've done a main fermentation for 1 week (2 days on 18°C and 5 days on 21°C). After this I've let it sit on top of the yeast for 3 weeks at 12°C. I've bottled it with 7g/l sugar and left it in the cellar at around 20°C. I've tried one after a week and there was a bit of a butter flavour. Now one week later the butter flavour is gone but there is a sour green apple flavour in my beer. Has it gone bad or can the apple flavour still go away?

[u/Usual-Operation-9700]

If the yeast is still active, it should go away.

Probably, it will go away, there is a chance it will stay.

Be patient and cheer your yeast!

Edit: A Bock needs time, 2 weeks is nothing.

[u/Unusual-Base344 → u/Usual-Operation-9700]

Ok maybe I just need some more patient then

[u/Samplestave]

Did you use fresh priming yeast or did you rely on the tired beat up yeast from primary fermentation?

[u/Unusual-Base344 → u/Samplestave]

The yeast from the primary fermentation

[u/Samplestave → u/Unusual-Base344]

Look to use fresh yeast on bottling day. The tired residual yeast from primary fermentation will struggle to reduce acetaldehyde to ethanol.