Butterscotch off-flavor. What next?

Alright... here's the deal. I became a little impulsive and I decided to brew beer in my apartment while the temperature outside was still a little warm. I kept the air conditioner on fairly consistently but the temp did peak at 75, maybe even 80 degrees.

After 3-4 weeks in the bottle the beer has an off-flavor of butterscotch or maybe banana. It's pretty apparent and the beer is essentially undrinkable. I've read a little about diacetyl, but I've found nothing about that flavor being aged out.

Basically, how likely is it that this beer will be drinkable? How long should I let it age or should I just dump it now and call it a day?

Anyone have a similar experience?

Let it sit for a month or so then taste it again.

No use dumping it until you have to.

Goatey said:

Basically, how likely is it that this beer will be drinkable? How long should I let it age or should I just dump it now and call it a day?

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Did you say DUMP?!?!?!?!

Please, get the words "Dumping Beer" out of your mindset.....

Since nothing pathogenic can grow in beer, that's a really silly worry and would be a waste of potentially excellent beer.

That's why I've been collecting success stories like this, to hopefully teach you overly worried new brewers the folly of your ways.


Most of the time a new brewer (and it's usually new brewers who do) is because they think something like that, though, and are actually tasting their beer usually when it is really green. Or they make a mistake and because of all the worst case scenarions they've come upon in books, they dump it thinking in their naievty that their beer will instantly go bad.

I wrote this awhile ago...it should be committed to memory...

You don't dump your beer, for making a minor little mistake. Your beer is hardier than that.

And you don't dump something because you think it's going to turn out bad. You only dump a beer that you KNOW is bad, and you give it at least a couple of months in the bottle before you even make THAT decision.

Read theses two threads that were compiled for nervous new brewers to realize that your beers are not a weak baby that is going to die if you look at it wrong.

https://www.homebrewtalk.com/f39/wh...where-your-beer-still-turned-out-great-96780/

Read this one especially

https://www.homebrewtalk.com/f39/ne...virtue-time-heals-all-things-even-beer-73254/

Our beer is really resilient despite the boneheaded things we do to it. And even if something appears to be wrong, often time and the yeasties go along way to correct itself.

And if everyone dumped their beer just because of a common thing like an airlock suckback, no one would be brewing. We ALL have had sanitizer from our airlock get into our beer at one time or another. There's a ton of panic threads on here about that, and the answer is always the same, RELAX.

I think about it in terms of my time and money, I'm not going to dump 30 or more dollars worth of ingredients, 6 hours of brewing time, and at least 2 months from yeast pitch to cracking the first bottle, on what could be a minor mistake (that may not even harm the beer anyway,) until I have exhausted all probability that the beer won't improve. And even then that means at least walking away from the bottles for maybe 6 months or more.

And so far I have never beer wrong.

After all these years of brewing I still haven't had a dumper.

And I've made some big mistakes.

But I have never had a beer that wasn't at least palatable, after all that time.

They may have not been stellar beers, but they were still better than BMC or Skunky Beers in green bottles that people actually pay money for.

So just read those threads and next time, relax, and give your beer a chance to prove how strong it really is.

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Read these stories while you relax...And especially erase the words "Should I dump this" from your thought process....

I'd be inclined to let it sit for 6 months before giving up, but then again you did not say what kind of beer and the recipe/yeast. Could be your yeast was inclined to give you those flavors.

In my own personal experience I've had beers improve and get better, but I've never had a beer that I thought was undrinkable turn out to be good. But that is just my own situation as I consider life to be too short to waste my time drinking stuff I don't like.

I've had beers that I thought were going to turn out undrinkable (and I have low standards) come out just fine after a few more weeks of aging (I tend to put them in the fridge too soon...)

And a couple that I did end up dumping because after 3 months is only got worse and I needed that keg! (I brewed a blonde while camping and had ZERO temp control. It was like 85-90 on July 4th weekend. ONly for a day and a half, but that was all it took to pretty much finish fermenting!)

The fact is, it usually gets better, so give it some time.

If it's indeed diacetyl, it can age out when bottle conditioning. I bottled a beer too soon once, rushing it for a competition, definite diacetyl aroma in the first couple bottles I tried. I handed one to my girlfriend and asked her first impression of the aroma and she said, "caramel popcorn". However, after another week at room temp, it completely went away. Any left over yeast can metabolize the diacetyl.

If it's esters because of high fermentation temp, it may always be there. You have nothing to lose by aging it, put it away and brew another batch to get your mind off of it.

If it is diacetyl, yeast is often able to clean that up. Look up a "diacetyl rest" that is used in lagers.

As others have said, just give it some time.

We would like some more info about what yeast you used along with your recipe and brewing conditions (temps and times).

If the "just wait" responses seem arrogant or smart ass-ish, then try this:

You can either do this to all your bottles or a portion of them if you just want to test it out.
Gently place your bottles horizontally and let them rest like that for a week. This gets the yeast back in suspension w/o aerating it. With the yeast in suspension it can go back to work on the diacetyl (which would be the buttery flavor, I despise it).
After one week, gently place the bottles upright again. This allows the yeast that is in suspension to fall through the entire bottle of beer, further cleaning up after itself.
After a day or two place a bottle in the fridge, let it chill for a few hours and decant it off the yeast cake and sample it.
It should either be completely gone of diacetyl or significantly reduced. If its not totally gone, waiting another week will prolly completely remove it.

Now diacetyl is produced as a by-product of the yeast fermenting (some lager yeasts and highly flocculating ale yeasts) AND from poor sanitation.

I had a bout for two batches where my old bottling bucket was the culprit of diacetyl production from poor sanitation. I replaced the bottling bucket and bottling wand and have never had it happen again (used same yeasts, even yeast cakes from "bad" batches). *note: it wasn't my sanitation practices that were wrong, just that the old plastic bucket was un-sanitizable)

Also note that since you said "bananas" to describe your off-flavor, it could be high fermentation temps with a yeast strain that doesn't like that and have nothing to do with diacetyl, but your girl did say buttery popcorn..........

hm... I appreciate your support Revvy(and everyone else)... I've made a few batches and some of them were quite good. I'm sure that these beers will be drinkable by the holidays.

I used a harvested Irish 1084 for an Imperial Irish, American 1056 for an Amber Ale and 3068 for a Dunkelweizen.

Now that I've gotten some feedback, I have a feeling that it's from being fermented at too warm of a temperature. In reality they're probably still a little green and I need to age them into something better. My diacetyl theory doesn't make sense. They're all ales and I don't think they were fermented TOO hot.

I'll try to remember to give an update in a few weeks just to let you know how this turns out.

I just sampled my OktoberFAST today after being kegged for 2 weeks (force carbed), and wow does it have a strong butterscotch taste. I brewed this with some US-04 in the low 60s (was in the high 50s for a few days) in a swamp cooler. It had a very slow start cause of low temps. I was worried about the temps shooting up which has been a reoccurring theme for most of my beers. I was able to maintain temp for 5 days after the yeast dropped out and then let it warm up to upper 60s for another 10 days. I then trasfered to secondary and was hit with a heat wave in mid ohio so the secondary got up to the low to mid 80s!! (not happy). I left it in the secondary for 2 weeks till kegging. At this point would it be good to let it stay in the kegerator and condition or should i take it out and let warm up for a few weeks? I dont have much yeast in the keg so should i pitch a half packet of US-04 and try and get it to clean up? Any advice would be much appreciated. This is my second attempt at the OktoberFAST and im starting to get very discouraged in myself

edit - Primary was for 2 weeks

ekjohns said:

I just sampled my OktoberFAST today after being kegged for 2 weeks (force carbed), and wow does it have a strong butterscotch taste. I brewed this with some US-04 in the low 60s (was in the high 50s for a few days) in a swamp cooler. It had a very slow start cause of low temps. I was worried about the temps shooting up which has been a reoccurring theme for most of my beers. I was able to maintain temp for 5 days after the yeast dropped out and then let it warm up to upper 60s for another 10 days. I then trasfered to secondary and was hit with a heat wave in mid ohio so the secondary got up to the low to mid 80s!! (not happy). I left it in the secondary for 2 weeks till kegging. At this point would it be good to let it stay in the kegerator and condition or should i take it out and let warm up for a few weeks? I dont have much yeast in the keg so should i pitch a half packet of US-04 and try and get it to clean up? Any advice would be much appreciated. This is my second attempt at the OktoberFAST and im starting to get very discouraged in myself

edit - Primary was for 2 weeks

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I would try an active pitch (starter) of yeast. If you put dry yeast in there, I'm afraid it will just drop to the bottom and do nothing. Pitch a starter at high krausen and check it after a week. You'll be pouring sludge for the first couple pints though.

So would this be a good plan of attack?

Make a small 250 ml starter from a frozen vial of pacman. (with a 20 ml step up) and about 12 Hrs into the 250 ml starter pitch the whole thing into the warmed keg let ferment for a week then rechill and carb?

If you don't mind having an Oktoberfest with a lot of yeast in suspension! But it is an ale oktoberfest, so you are obviously OK with that.

You are going to have to wait a bit longer than you originally wanted to to let the yeast clean up after itself......its going to re-green your beer, but hopefully it will get rid of the diacetyl.


From Wyeast:

1084 - "Fruit and complex esters will increase when fermentation temperatures are above 64°F"
3068 - "This yeast strain produces a beautiful and delicate balance of banana esters and clove phenolics. The balance can be manipulated towards ester production through increasing the fermentation temperature, increasing the wort density, and decreasing the pitch rate."

So you used a mixture of these yeasts, plus 1056? That's a pretty crazy mixture. Why did you add the wheat beer yeast? That could be the sole cause of why you don't like the beer's flavor profile. Plus you fermented warm, and with those yeast esters are going to be abound at high temps.

I think you made a bad choice on yeasts. I would have stuck to one malty ale yeast. Which really isn't any of those.

My diacetyl theory doesn't make sense. They're all ales and I don't think they were fermented TOO hot.

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Why does that rule out diacetyl? It can be from the yeast or from contamination (or even one of those yeast cakes was contaminated?) I do believe at least one of the ale yeasts is prone to diacetyl production.


Next time you are going to brew it in the correct lager form, right? It can't be worth the extra effort you have gone thru to make it an OktoberFAST instead of an Oktoberfest.

I used US-04 according to BMC instructions. After the about 2 weeks between 58-62F I let it warm up in the secondary to upper 60s but fermentation is done at that point so i thought alot of the off flavors wouldnt get produced. At this point i was thinking about adding pacman as it is the only liquid yeast i have to make a small starter besides spending $7 on yeast just to try and clean up the beer. Do I need to temp control when i re-pitch since there isnt going to be alot of fermentation more just clean up?

You probably want it a little warmer so the yeast can be more active. Hope it works out, I've never tried something like this. S-04 is super flocculent, diacetyl in beer is a hazard of using super flocculent yeast. You might get a bit more attenuation if you pitch a different strain as well.

I think funkswing thought you were the person who started this thread, ekjohns. Looks like he combined things from two different posters.

smizak said:

You probably want it a little warmer so the yeast can be more active. Hope it works out, I've never tried something like this. S-04 is super flocculent, diacetyl in beer is a hazard of using super flocculent yeast. You might get a bit more attenuation if you pitch a different strain as well.

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Exactly - the yeast drops out of suspension before it has time to clean up the diacetyl that is produced during fermentation.....its not just a lager thing.

mojotele - looks like I did......but that is still a crazy yeast mixture (if that is indeed what he did).

ekjohns - 58-62 F are pretty low temps for that yeast. That is only going to emphasize your diacetyl problem, b/c the lower temps also speeds up (the already fast, b/c of the yeast strain) the flocculation.

Okay Ill try some pacman and let it sit in upper 60s to low 70s. Thanks all for the help. I did take a hydro reading at the FG was 1.021 which is def. higher than i wanted (shooting for 1.017) so it seems the yeast didnt finish their job. ill try and give another yeast some try to salvage the beer.

Sorry, I didn't explain that these were three different beers. I have three 5-gallon batches of each beer.

I don't think I'm quite advanced enough to mix yeasts.

I essentially have 150 bottles of beer with some serious off-flavors. Hence why I posted this.

I like your explanation though. It's pretty rational and it puts things in perspective for me.

funkswing said:

If you don't mind having an Oktoberfest with a lot of yeast in suspension! But it is an ale oktoberfest, so you are obviously OK with that.

You are going to have to wait a bit longer than you originally wanted to to let the yeast clean up after itself......its going to re-green your beer, but hopefully it will get rid of the diacetyl.


From Wyeast:

1084 - "Fruit and complex esters will increase when fermentation temperatures are above 64°F"
3068 - "This yeast strain produces a beautiful and delicate balance of banana esters and clove phenolics. The balance can be manipulated towards ester production through increasing the fermentation temperature, increasing the wort density, and decreasing the pitch rate."

So you used a mixture of these yeasts, plus 1056? That's a pretty crazy mixture. Why did you add the wheat beer yeast? That could be the sole cause of why you don't like the beer's flavor profile. Plus you fermented warm, and with those yeast esters are going to be abound at high temps.

I think you made a bad choice on yeasts. I would have stuck to one malty ale yeast. Which really isn't any of those.


Why does that rule out diacetyl? It can be from the yeast or from contamination (or even one of those yeast cakes was contaminated?) I do believe at least one of the ale yeasts is prone to diacetyl production.


Next time you are going to brew it in the correct lager form, right? It can't be worth the extra effort you have gone thru to make it an OktoberFAST instead of an Oktoberfest.

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ekjohns- A bit of a warning here. When you pitch that pacman starter, have your keg lid ready...The carbonation in the keg will rush right out the top and you'll lose a good bit of beer...not to mention make a mess. Trust me....It just happened to me last weekend! But it did work in my case.

WVbrewer, could you please explain this a little more? I dont have a spunding valve (not sure if thats the right spelling) and I was planning on pitching the starter and hooking up an blow off valve through the gas in (which would result in loss of carbing). Since I am not adding any more sugar do I need to do this or should i just put the lid on and let sit? This is the only keg I got going so I could hook up the tank turned off and read the pressure through the tank regulator

I wouldn't worry about a blowoff. In fact I'd discourage it because it will just blowoff fermented beer...Picture a glass of champagne with a bit of fruit tossed in. The carbonation rushes to the fruit and sometimes overflows the glass (a "nucleation point" is the term for this I think). Now picture a carbed keg with tons of tiny "fruit" (yeast in this case). It's gonna foam up and go all over the place. Just put the lid on quickly and wait a 3 days or so. The yeast won't attenuate the beer much more if any, so no need to vent. You can vent after a few days to be safe, then put it back on gas in the fridge. The yeast will settle out and hopefully you'll be drinking carbed non-butter beer in anotherf ew days.

3 days wow! i was thinking it would be like 2 weeks awesome. Thanks Ill report how it turns out. Hopefully no volcano beer. I got some beer brewing as we speak with so pacman so ill prob take a small amount pitch in a 250ml with some yeast nutrients and pitch at high kruasen