Tainted batches - what is wrong?

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Brewsit

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I have had the same thing go wrong in three out of four of my last four batches, and I can't figure out what it is. They all have had the same overpowering ester (banana-ish) flavor, and a hot, almost burning sensation that makes the beer undrinkable. I thought it might be an infection in my equipment somewhere, but I wanted to get some other opinions.

I used the same equipment, and I'm good about sanitation, and use an oxyclean soak, thorough rinse and starsan soak. All of my equipment is very new, and I keep it clean, dry and indoors.

I ferment in a home-made fermentation chamber, insulated and controlled with an ebay temp controller, and temperature probe inside the fermenter, everything sealed well.

It happened in the first batch, a pale ale fermenting at 70F. The second batch it did not happen to, but it was a California Common fermented at 58F.

It happened to the third batch, a Best Bitter at 68F, and again a Saison, fermented at 74, raised to 77 through the fermentation (I used the AHS Saison blend yeast which calls for about 72-78). This one is still in the fermenter after three weeks, and I drew a sample, and that same smell of bananas is back again, along with the hot/burning sensation.

What the heck am I doing wrong here, and is this last batch salvageable? I have thrown out the first batch, and the Best Bitter is in kegs at room temperature, I'm hoping maybe there is something that can be done.
 
I think it's all in the temperature control. I'm convinced that for most ales you need to ferment between 60-65 and not much higher. Your Belgians are different obviously and are supposed to have that phenolic taste so the saison doesn't surprise me.
 
But am I really going to get the same off flavor in three completely different yeasts? I forgot to mention the first yeast was AHS Persica, the third was Burton Ale.
 
Yep. Each strain of yeast is designed to impart different flavor profiles...it makes sense that each one will react differently to temperature.
 
I haven't calibrated the temp controller, I guess I figured it would be pretty close as it's digital. I didn't really have any reason to believe it was off, either, as I had an analog one there for a while that I knew was accurate, and it was good.
 
Oops, wrong answer...I see what you're saying. On the flip side, most of my ale yeast strains get that way when fermented too high. Honestly, a lot of that might age out also.
 
Yea, I just don't get it. It's very prevalent, and I don't know what the heck is wrong. Very frustrating.
 
You don't list any of the yeast strains but aside from the Saison it all points to high ferm temps which will cause a lot of fruity esters and fusel alcohol production.

The fuselage should diminish as the beer conditions but the esters probably won't that much, although they may mellow.

If you go to the manufacturers website you can look at the temp ranges for each strain. Assume that if you are at the higher end you are fermenting hotter than ideal, being more mid range to low for less water/fusel production.
 
Ya +1 on the temp, also sometimes even if you are fermenting within the manufacturers recommendations for temp, if you go on the higher end it can produce some of the flavors you are talking about. I got between 66 to 68 for my ales in the first few days and then try to kick it up a bit if I can towards the end to help attenuation.

The first 72ish hours of fermentation are very important for ester production and I believe the first 24 are some of the most crucial. So, if your beer is cooling down from say 80ish degrees (what tempdo u pitch?) to what you set your temp at for the first 24 hours then that might be your problem there.

The CA common probably didn't have as much of a problem due to lower temps and lagering.

The bitter is a little surprising but if you do what I mentioned above then that would make sense.

If you don't like the beer then you could make a second batch and blend them which would probably lessen the flavors.
 
You don't list any of the yeast strains but aside from the Saison it all points to high ferm temps which will cause a lot of fruity esters and fusel alcohol production.

The fuselage should diminish as the beer conditions but the esters probably won't that much, although they may mellow.

If you go to the manufacturers website you can look at the temp ranges for each strain. Assume that if you are at the higher end you are fermenting hotter than ideal, being more mid range to low for less water/fusel production.

I did list them, just further down. AHS Persica ale and White Labs Burton Ale. I was always well within the manufacturer's recommended temperature range, and had the probe inside the middle of the fermenter, which means that the core temperature never got above the recommended temperature. This is why it frustrates me. The Burton Ale, I even started it cold and slowly raised the temp over the course of a few days. Every batch I also made sure that the wort was below the target fermentation temp before pitching, aerated, always used a big (3L) starter, told it bedtime stores, rocked it to sleep, I don't know... am I missing something?
 
Ya +1 on the temp, also sometimes even if you are fermenting within the manufacturers recommendations for temp, if you go on the higher end it can produce some of the flavors you are talking about. I got between 66 to 68 for my ales in the first few days and then try to kick it up a bit if I can towards the end to help attenuation.

The first 72ish hours of fermentation are very important for ester production and I believe the first 24 are some of the most crucial. So, if your beer is cooling down from say 80ish degrees (what tempdo u pitch?) to what you set your temp at for the first 24 hours then that might be your problem there.

The CA common probably didn't have as much of a problem due to lower temps and lagering.

The bitter is a little surprising but if you do what I mentioned above then that would make sense.

If you don't like the beer then you could make a second batch and blend them which would probably lessen the flavors.


On the first batch I did pitch around 78-80 and dropped it from there, but the others I dropped before pitching. I think the flavor is so strong that I wouldn't blend it with any beer that I thought was worth drinking, unfortunately. Maybe six months to year of aging?
 
Well that's strange as it sounds like your doing everything right, but your getting flavors that would indicate high ferm temps.

It is possible that your thermometer is off so I would try checking the calibration on all of your therms.

Do you use any sort of cheap plastic or PVC in your process because that may be a source of some of hot solventy flavors.

I am also wondering if you use starters and how long you leave your beer on the yeast?

Stressed out yeast can cause these sorts of flavors as well which would be a result of under pitching.

It's also possible that some of these flavors could be coming from oxidation but unlikely because that usually shows up in months and not immediatly.
 
Aging beers 7ish+ % shold be fine. Beers lower than that unless you are lagering or something don't tend to hold up well for too long.
 
No cheap plastic or PVC, everything food grade HDPE and stainless steel. I usually calculate the pitch rate to at least get in the ballpark, and do a starter every time. It's strange too because before, on batches that I didn't use a starter, didn't regulate the temp as much, and pitched warm, I never had this problem.

This is why I was thinking it is an infection, but does an infection really show up as a hot burning sensation and high esters?
 
+1 on verifying/calibrating thermometer and the temperature controller.

Also on stressed yeast possibilities.
 
It really sounds like a temperature issue to me.

I brewed a "Banana Bread Ale" for my wife using a Hefeweizen yeast. It has a faint banana flavour.

I later brewed an American Pale Ale with US-05, and inadvertently fermented it a little too warm. It has an overpowering banana flavour, much more noticeable than the one that was SUPPOSED to taste like banana!
 
ya problem is it sounds like he is controlling everything properly, unless his thermometers are off...
 
What are you doing with your water?? Sorry if I missed it..

Tap water? RO water? Cut with something? Water additions?

Sounds like your temps are off, IMO.

Also.. starters... Are you letting these get hotter than hell, or controlling the temp somewhat on those? Crashing them, or adding all of the starter?

If you are making these huge 3L starters, and dumping them in whole, you are adding some oxidized, nasty warm, fermented "beer" to your beers. 3L is alot of crap to be tossing into the wort. Make a starter next time and taste it.. Taste familiar to what you are finding in your beers?
 
What are you doing with your water?? Sorry if I missed it..

Tap water? RO water? Cut with something? Water additions?

Sounds like your temps are off, IMO.

Also.. starters... Are you letting these get hotter than hell, or controlling the temp somewhat on those? Crashing them, or adding all of the starter?


Using RO water, usually no additions but on the best bitter I added a little bit of salts calculated to bring out the bitterness. The starters are done on my kitchen counter, usually mid 70's in the house at the hottest. I crash them, decant, let warm up to room temp and pitch.

So are we fairly certain that this isn't from an infection? I just find it really strange that it's the same dang flavor each and every time. I know that there are a ton of variables, but I try to do a fairly good job of controlling as many as I can.

If my temps are off, that means that the temp probe is dead wrong on the ebay aquarium temp controller... and there isn't any way to change that, as far as I know. I don't recall anyone really having any issues with that, though.

Let's assume that the temperatures are OK... is there still something I'm missing, or is the temperature the ONLY thing that it could be?
 
Your ale temps are too high. Some ale yeasts might "tolerate" 70F, but none of them (that I've used) put off clean beer when fermented that warm. Just try to lower your fermentation temperatures to 64 on your ales and see if that fixes it. Don't reinvent the wheel even if you think my idea is way wrong. Just try it. Phenolic/Rocket Fuel always tastes the same, and all those yeasts are capable of putting off those same chemicals.

I sense you wanting to believe it's something else, but in my 50+ batches of beer, the reason for those off flavors have always been the same. Too warm fermentation temps.

There's collective wisdom here, your other responses almost all ask about temperature. If you have to tweak something, tweak that.

PS, you never mentioned pitch temp (that I saw, I didn't read all the posts closely). Pitching too warm will give you this effect as well. I always ferment my ales at 64ish through high krausen then ramp up to 69f (1 degree at a time) by the time the krausen has completely dropped. When I'm fermenting at 64, I'm trying to pitch LOWER then that so the yeast can warm up to the job slowly.

Think of it as a yeast party. If you start them off doing shots (warm temps) they're going to get sloppy drunk very quickly and perhaps trash your house before the night is up. If you start slowly, you may have some happy drunks at the end, but the collateral damage will be lessened.
 
Your ale temps are too high. Some ale yeasts might "tolerate" 70F, but none of them (that I've used) put off clean beer when fermented that warm. Just try to lower your fermentation temperatures to 64 on your ales and see if that fixes it. Don't reinvent the wheel even if you think my idea is way wrong. Just try it. Phenolic/Rocket Fuel always tastes the same, and all those yeasts are capable of putting off those same chemicals.

I sense you wanting to believe it's something else, but in my 50+ batches of beer, the reason for those off flavors have always been the same. Too warm fermentation temps.

There's collective wisdom here, your other responses almost all ask about temperature. If you have to tweak something, tweak that.

PS, you never mentioned pitch temp (that I saw, I didn't read all the posts closely). Pitching too warm will give you this effect as well. I always ferment my ales at 64ish through high krausen then ramp up to 69f (1 degree at a time) by the time the krausen has completely dropped. When I'm fermenting at 64, I'm trying to pitch LOWER then that so the yeast can warm up to the job slowly.

Think of it as a yeast party. If you start them off doing shots (warm temps) they're going to get sloppy drunk very quickly and perhaps trash your house before the night is up. If you start slowly, you may have some happy drunks at the end, but the collateral damage will be lessened.

You're right, I do want to believe it's something else, because I didn't ever have this issue before with temp... I did mention pitching colder and letting it warm up.

I will definitely adjust the temperature to the lowest end of acceptable and see what happens. I'm just really surprised that I got the same off flavor in the saison, which is supposed to ferment warm. How do guys get away with fermenting at 90F without problems, and I start mine below the recommended temp range and still end up with problems? I used to ferment in the closet where the best in temperature control I got was slightly lower than ambient temp (around 68 external) with no issues, then when I move to a highly controlled environment, fully insulated and controlled within .3 degrees, it gives me these problems...
 
How are you measuring the temp of the wort? Thermowell? Probe taped to the side of the fermentor? Probe hanging inside chamber?
 
Just to reiterate,
Just because the thermometer and controller is digital doesn't mean it is accurate. Could be the probe/sensor, could be the unit and the way it activates.

Find another thermometer and place it in the chamber and see what it reads and be sure to be using a calibrated instrument to make sure it is not off also. You might be surprised.

For example: I have two hydrometers and they were purchased at the same time and calibrated to read 1.000 in distilled water. I have had them for many years and always verify their calibration once per month. Last week I went to verify and one of them is now off by .004 with no changes in it's usage and care

For Example: I have two calibrated thermometers, 1 digital thermapen, one laboratory grade, they are within 1 degree of each other and I use them to verify my Johnson Digital Temperature controller for each batch I ferment. It reads temperatures that are higher by two degrees so When I set the temperature I adjust for this 2 degree difference.

You purchased a unit on ebay and are assuming it is correct and it very well could be off. There is a big difference between fermenting at 67 or 70 and that little difference with the yeast can throw off many off flavors that otherwise wouldn't be there.
 
So if you are assuming it's the temp controlling unit/thermometer....

When did you start using that.. About the time you notice a change in the flavor and quality of your beers?

Work backwards.. When did you first notice it, and see what you added, subtracted, or did different in the process from there.

If you are using RO water, you might want to look into adding stuff back. Yeast need some nutrients in the water, and it'll help with flavor as well.
 
You're right, I do want to believe it's something else, because I didn't ever have this issue before with temp... I did mention pitching colder and letting it warm up.

I will definitely adjust the temperature to the lowest end of acceptable and see what happens. I'm just really surprised that I got the same off flavor in the saison, which is supposed to ferment warm. How do guys get away with fermenting at 90F without problems, and I start mine below the recommended temp range and still end up with problems? I used to ferment in the closet where the best in temperature control I got was slightly lower than ambient temp (around 68 external) with no issues, then when I move to a highly controlled environment, fully insulated and controlled within .3 degrees, it gives me these problems...

FWIW, I'm personally skeptical of anyone claiming they can ferment any yeast at 90F "without problems".

I have fermented ales in the low 60s dozens of times without a problem, but I've fermented them above 68 a couple times and had a problem every time (Problem for me with an American Ale is too many esters/phenolics). Sorry I didn't see where you said you pitch low and let it warm up, I was just trying to throw every idea I had at you in effort to help out.

I'll bet you dollars to donuts decreasing the temp will fix your issues. Please follow up after your next batch.

Edit, your last sentence is a clear cut case for calibration isn't it?
 
FWIW, I'm personally skeptical of anyone claiming they can ferment any yeast at 90F "without problems".

I have fermented ales in the low 60s dozens of times without a problem, but I've fermented them above 68 a couple times and had a problem every time (Problem for me with an American Ale is too many esters/phenolics). Sorry I didn't see where you said you pitch low and let it warm up, I was just trying to throw every idea I had at you in effort to help out.

I'll bet you dollars to donuts decreasing the temp will fix your issues. Please follow up after your next batch.

Edit, your last sentence is a clear cut case for calibration isn't it?

I completely agree but thought I would jump in on the 90 thing....
I just brewed a Saison with WY3724 and had the typical issues with it sticking at 1.030.

I followed up with the folks at Wyeast and they have recommended that this particular strain actually get pitched at 80 and ramped up to 90-95 as it slows to prevent the sticking-this is directly from the folks at Wyeast so yes, there are a few strains that actually like it hot and produce the desirable flavor profiles at those temps but definitely not the norm...........
 
I completely agree but thought I would jump in on the 90 thing....
I just brewed a Saison with WY3724 and had the typical issues with it sticking at 1.030.

I followed up with the folks at Wyeast and they have recommended that this particular strain actually get pitched at 80 and ramped up to 90-95 as it slows to prevent the sticking-this is directly from the folks at Wyeast so yes, there are a few strains that actually like it hot and produce the desirable flavor profiles at those temps but definitely not the norm...........

Fair enough ^

Even this one exception still doesn't pitch and ferment during the early hours of fermentation at those temps. I actually do a similar thing with my ale yeasts, but I try to pitch at 64 or lower (as low as 61-62) and leave it at 64 for the bulk of active fermentation. When it starts to slow down I'll ramp it up 1F per day until I'm just below 70, and I don't mind letting it sit in the low 70s for up to a week if I'm dryhopping and active fermentation is totally over.

Also, I want to edit and say I'm much more experienced with Ales then Saisons...thanks for chiming in to round things out :mug:
 
Fair enough ^

Even this one exception still doesn't pitch and ferment during the early hours of fermentation at those temps. I actually do a similar thing with my ale yeasts, but I try to pitch at 64 or lower (as low as 61-62) and leave it at 64 for the bulk of active fermentation. When it starts to slow down I'll ramp it up 1F per day until I'm just below 70, and I don't mind letting it sit in the low 70s for up to a week if I'm dryhopping and active fermentation is totally over.

Also, I want to edit and say I'm much more experienced with Ales then Saisons...thanks for chiming in to round things out :mug:

We are totally on the same page:D
I make starters, pitch cold and ferment no higher than the 65 for just about every ale I make, as they slow I will raise and swirl until they finish but I'm still really no higher than 68 by the time they are done.:tank:
 
You guys might be right about the temp calibration. I am using a stainless thermowell with the probe at the bottom of it. I will calibrate the temp controller and get back with the results of that.
 
Where do you measure the temps you mentioned? On the fermenter? Ambient air?

What yeast(s) did you use on the batches that had the bad flavors? Some yeasts (like Nottingham and sometimes S-04) get nasty above 68*F (measured on the bucket).
 
Update:

So, I went out to take a quick temperature comparison with the thermometer that I THOUGHT was calibrated... I calibrated it with boiling water and it was good. However, at the lower end, I think it might be off. In a cup of warm water, it read 95F when the temp probe read 90. At first I thought, "yes, there is my problem". However, I checked it against a digital meat thermometer AND a digital medical thermometer, and both read the same as the temp probe. So, if three out of four thermometers read similarly, I am lead to believe that my analog thermometer is off by 5 degrees. Let me know if this seems like it's too far a stretch.
 
put them all in boiling water and see if they read 212 too. seems like you might be right though...
 
Sounds like the issue but also check it in ice water at the low end as well. 5 degrees is a pretty big discrepancy.
 
Checked against boiling water, and they all read the same, so on the high end everything looks good. Checked against ice water, everything reads the same as well, and accurate. For whatever reason, the analog thermometer is way off between 70 and 100 or so. Checked the digital meat thermometer against the probe and they are less than a degree from each other.

I was thinking about something, let me know if this sounds off... with the mass of the fermenter, and the probe being about halfway down and halfway in (half the distance from the center and outside wall), is it possible that the fermenting wort is warming enough on the outside of the fermenter and allowing the conditions for too high of fermentation temperatures? The A/C unit only kicks on when the probe gets to the right temperature, but the ambient air is warmer than the mass of the container usually, until the a/c runs. The entire thing is insulated, and stays rather cool, so I don't know.

On the next batch I am going to aim for the very lowest temp that the yeast will tolerate and see what happens...
 
Analog thermometers can take a bit to adjust IME.

I doubt the wort would have that large a temp swing from one location to another in the vessel, it's not going to swing that quickly as its a pretty good insulator by itself, think swamp cooler and the insulation that provides.

I would try the lower end next time as well and see how it goes.
 
I owe a follow up to this thread. Since the last update, I have dropped the fermentation chamber temp to 65 and have had zero issues. The saison mellowed out and was actually a favorite of mine and of everyone who drank it. The best bitter that I made has mellowed out a lot, but there is still a hint of off flavor that makes it not the greatest thing to drink, especially with other great beers available. I think temperature was definitely the issue.
 
It's nice to see a "what's wrong" thread that ends with some resolution. Congrats. That was my most frequent early error...ferm temps. Now I learn what my yeast likes and it gives me what I like....delicious beer! :mug:
 
Banana is an ester called isoamyl acetate. It is formed when isoamyl alcohol combines with acetic acid. While high fermentation temperatures can cause yeast to produce isoamyl acetate, poor health and under-aeration also lead the formation of the ester. With most yeast cultures, isoamyl acetate production is mother nature's way of telling us that the culture experienced stress during fermentation.

Anyway, it is nice to see that there was a happy ending to your problem. I am not that patient. I dislike the taste of isoamyl acetate so much that I do not hesitate to dump batches that show as much as a hint of that ester.
 
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