Banana flavour?

[Hopasauraus]

I have made a pale ale and it was great then after a while it got banana flavours to it which i dont like what causes this?

 

[MHB]

See Isoamyl Acetate

Copy of Complete Beer Fault Guide attached, well worth copying on to any brewers desktop.
If you open the Fault Guide and search for Banana you will find a bunch more references
Yes-yes I know a crappy pun
Mark

 

[Nickedoff]

That's gold @MHB

 

[MHB]

I find it very handy, especially when people use weird descriptors like soggy goat, at least it gives you somewhere to start.
Note that the author has given permission for non-commercial reproduction, so its a free resource that we can all share, and the author would never need to pay for a beer if he was anywhere near me.
Mark

 

[Danscraftbeer]

Also recognizing this flavor is unwelcome to some styles then very welcomed in other styles. I've never got that banana flavor even when it was an expected result. Like Coopers cultured yeast it smells like fruit salad in the starter but cuts down to very clean (minimal esters) in the end. Re-I'm well convinced it has all to do with yeast pitch rate and temp control in variance of flavors on any yeast.