Banana Taste After Fermentation

[tahzan]

Measured my toucan Stout/Draught after 8 days and it had fallen from 1054 to 1014. Tasting note stated 'Bitter with strong burnt aftertaste, some roasty notes. Looking forward to it rounding out'.

Wen to bottle today after 16 days and the samples have been banana flavoured and thin. Is it common to have an infection after main fermentation has occurred? The two cans were mixed on a saf-04 yeast cake from a 3kg ESB stout kit (which is more than fine). Cold tap water used only. Ferment temps have been between 21-24 generally (under the house), although there was a hot day on Thursday where it got up to 26 but fermentation had finished by then.

I am loath to give it to the lawn - was thinking that it may clear with a long time in secondary and maybe some hops, followed by long rest in bottle?

p.s. if it is lost will it do my Sir Walter buffalo any good?

 

[Adamt]

Banana is a fermentation by-product in many ale yeasts, produced when the yeast is under stress either by bad yeast health or higher temperatures (21-24C comes under this). Esters will diminish with time in the bottle. Do not turf it, definitely bottle it. You will taste different things when the beer is colder (less esters will vent, beer will seem thicker), and carbonated (gives an impression of fullness).

A mild banana/fruitiness can definitely suit a stout. Sample regularly!

 

[tahzan]

Thanks - good to know that time can heal in the brewing world too!

Will a secondary with some hops help it along or should I bottle asap?

 

[Adamt]

I would bottle it now (assuming fermentation is done), you may find you like it as-is (cool and carbonated) but if you don't you can just set it aside and forget it for a month or two!

If you decide to bulk condition it though... I wouldn't bother too much with the hops, let the malt shine!

 

[GMK]

It would help to know what kit and yeast was used...

Would allow us a better chance for a better reason why etc...

 

[Adamt]

GMK: 3kg ESB stout kit and S-04 yeast. Unless he lied in the thread opener!

 

[tahzan]

Coopers Stout and Homebrand Draught tins onto Saf-04 yeastcake from ESB Stout kit. Cold tap water only and plenty of stirring with sanitised spoon dried out on my (lit) gas hob to be sure!

Edited for dyslexia.

 

[dr K]

Turf it, SO4 is an ale yeast yes, and ale yeasts do throw some fruity esters (though SO4 is rather bland), but banana has no place in the SO4 profile, yes you have an infection and the sooner a brewer recognises infections (they do not all taste like metho mixed with plastic) the sooner the brewer becomes a better brewer.

K

 

[jonocarroll]

Turf it, SO4 is an ale yeast yes, and ale yeasts do throw some fruity esters (though SO4 is rather bland), but banana has no place in the SO4 profile, yes you have an infection and the sooner a brewer recognises infections (they do not all taste like metho mixed with plastic) the sooner the brewer becomes a better brewer.

K

Is it ever correct to throw away a brew that isn't offensive tasting? Sure, it may very well be infected, but if it isn't disgusting (though, it may be - not enough details provided) surely the best bet is to bottle it and see what happens. What if it isn't actually an infection and it's been misdiagnosed from across the internets - wasted brew.

I understand where you're coming from K, but a lesson can be learned without discarding the entire batch just yet.

 

[dr K]

Is it ever correct to throw away a brew that isn't offensive tasting?

If it were then then I would chuck out far more than I do now, indeed it would eventually click that my process was brew and turf!!
I guess people, and I am one of them, get a bit wedded to style guidlines, if you want to brew a banana flavored stout then go for it, use a whaet yaest and use a wheat beer fermentaion profile, follow the 30 rule, if you use a reused cake of S04 and your Stout ends up tasting like bananas and you like it then by all means keep it, at worst its better then megaswill you know, accept the infection and keep on brewing.

K

 

[jonocarroll]

I guess people, and I am one of them, get a bit wedded to style guidlines, if you want to brew a banana flavored stout then go for it, use a whaet yaest and use a wheat beer fermentaion profile, follow the 30 rule, if you use a reused cake of S04 and your Stout ends up tasting like bananas and you like it then by all means keep it, at worst its better then megaswill you know, accept the infection and keep on brewing.

K

Style guidelines are a great target to brew to, and you'll certainly improve your brewing by doing so, but it's terrible advice to suggest that if it doesn't fit the guidelines it belongs on the lawn. Learn what that flaw brings to the beer over time and you'll know why it's called a flaw.

I've recently made a fail ale - don't ask what went in it - point is though, I still bottled some of it. I know that right now it tastes something like a cross between feet and arse, but I'll see what it tastes like after 6 months, 12 months.

If you're gonna start telling people to turf any beer that doesn't fit the guidelines, you'll get RSI from typing the same thing over and over. Just horrible advice IMHO.

 

[kevnlis]

The banana taste is most likely iso-amyl acetate. This most certainly is a bi-product of high temp (above 19C) S-04 fermentations. I would drink the beer if you reckon it tastes alright. Might not be to style, but I bet it is still a nice drop

 

[dr K]

If you're gonna start telling people to turf any beer that doesn't fit the guidelines, you'll get RSI from typing the same thing over and over. Just horrible advice IMHO.

I am not and was not talking about style guidelines, I was, however, talking about yeast profiles. For the last 4-6 months my beers have all been 1038-1042 SG and overhopped, they are not brewed to a style guidline and I have not thrown them out.
As i RSI'd i noted that if you want to brew a banana stout then do so and use the regime and yeast to do so, a spontaneous banana stout, even if to the mother's eye is wonderfull is none the less infected, as I RSI'd, accept it as an infection, enjoy it and brew on.

K

 

[Adamt]

Dr K... though I understand your opinion, please read my first post in this thread:

Banana esters present in the beer will seem much more prominent (to the nose and hence also to taste) at higher temperatures and I think this may be a case of it. While the beer may not be brilliant now, given a few months in the bottle it could likely turn out fine.

If brewers turfed everything that didn't go quite right, how would we have lambic? :icon_drool2:

 

[MarkBastard]

My opinion: it's not infected. S04 produces strong banana at higher ferment temps, same thing happened to me about a month ago. Most of the 'taste' is actually banana aroma. I got rid of mine fairly quickly by burping the keg a lot and generally it was gone within a week.

I'm not sure if secondary would drive it off, possibly secondary with a crash chill. I had a feeling with mine it was the combination of lower temps and burping the aroma off.

 

[tahzan]

I have plenty of bottles around so I think I'll stick it up the dark and cool end of my underhouse area and forget about it for a few months. I will try a chilled one in a week or two anyway to assess any changes. If it hasn't improved in a few months I'll still have learnt something about rescue-ability(?)

What surprised me was the late development of the fruitiness. Maybe it is more of an aroma thing. When I opened the top of the fermenter last night the smell was very strong from the krausen leftovers on the fermenter walls. Once you have a flavor/smell on the brain I think you tend to look for it - I had a bottle of Grolsch whilst I was bbqing and could swear it had banana flavours too. Couldn't shake it on the second bottle and had to switch to Shiraz.

 

[boingk]

I had this something chronic with a K&K ale I did a while ago with a recultured Coopers yeast. Heatwave plus no fermentation fridge equals banana heaven. Its mellowed a bit, but is still reminiscent of a hefeweizen. I don't mind it.

Another thing I noticed while drinking Guinness and then having a Coopers Pale is that it has a fair amount of banana. Reminds me of having Streets Paddlepops as a kid, don't mind it at all.

Cheers - boingk

 

[Brewer_010]

Nobody has answered one of the more important questions asked by Tahzan. Chuck your cooked brew on the Sir Walter, Tahzan, the lawn will love you for it.

In all the times I've used S-04 (5+) I've never had a banana ester, so it's been fermented too high / too much yeast and I'd probably hoof it and notch that one up to experience. In two months time the beer will probably be very ordinary, but up to your personal preference. Using an entire yeast cake for a ferment requires good temperature control to avoid hot temps. If I use the slurry from a previous brew I scoop out half a litre or so then pitch it into a new fermenter.

Cheers

 

[tahzan]

Thanks #010 - I did use the whole cake and now realise this was an error. I think someone mentioned that a tablespoon's worth would suffice in future. I wasn't around in the first two days of the ferment and no doubt it generated a bit of internal heat.

The government and her mates drink sparkling water aplenty so I have a load of 1.5l bottles to chuck it in to see if time can make a fool of me! The lawn may yet benefit - good to know it won't have the same effect as my dogs' homebrew.