Weizen has gone from banana to phenol?

[jat147]

Howdy,
So I did me a germanish weizen at the start of June using WLP300 liquid yeast, and after 2 weeks in the bottle is was pretty nice.
Fairly smooth all round with a decent flavour of banana, which I haven't seen much of before due to not previously having any temperature control. Now I've got a controlled FV I did this brew at 20C, which I thought would be good for the strain?
Now its been bottled for a month, the flavour has changed in a big way, banana has gone only to be replaced by a pretty strong flavour of phenol?

What has happened, did I ferment too high? Mash was a little lower than I would have liked at 67.5, but that wouldn't make this happen? would it?

Any WLP300 users able to throw me a bone please? Cheers.

 

[TyTanium]

Have the bottles been in the fridge? I believe cold temperatures cause some esters to drop out, revealing more of the phenol character.

 

[jat147]

No, them all stored at room temp to carbonate. Which reminds me, I might have gone in a bit heavy with the priming sugar as they're
a little too lively when you open the caps. Dont know if that is relative or not??

 

[TyTanium]

No, them all stored at room temp to carbonate. Which reminds me, I might have gone in a bit heavy with the priming sugar as they're
a little too lively when you open the caps. Dont know if that is relative or not??

That's good for the style. They'll be less lively once chilled.

 

[jat147]

Thanks very much Ty, you're right they are less of a problem when chilled but the level of carbonation does seem to increase for several weeks - I'm guessing its because my conditioning temp is too low?
I'm getting off topic ... anyone seen a chart of temps for WLP300?

 

[TyTanium]

I saw this once and have found it to be fairly accurate, though many report solid banana at lower temps (62ish):

At 63º(actual ferment temp) you will get a large amount of spice and clove with light banana/bubblegum.
66º is a fair balance,
68º throws banana and bit of the sweeter gum and candy flavors (think Hacker Schorr and Fransiskaner),
70º is pushing your luck but can be good if you really prefer the sweeter stuff,
higher than 70º will not be good (lots of heavy alcohol medicinal and sickly esters).

 

[Pilgarlic]

Development of phenolic off flavors and excess carbonation after bottling are consistent with and might indicate a wild yeast infection.

 

[jat147]

Ahh, perfect! Mine went at 68F which seemed ok at the time, but if I could do it again I'd drop that by a few degrees I think?
I say 'if' .... I guess I actually mean 'when' I make it again.
Thanks again!