Estery again???

[carvin160]

All - my first batch came out estery, and with uneven carbonation. But i had an awesome time, and thought I learned my lessons.

My second batch is in primary for 2 weeks now. I took a reading after 10 days, and again on two weeks to see if I should bottle this weekend. First reading was just above expected FG, and tasted awesome, no off smells - smelled and tasted like a brown ale!

Second reading is at expected FG, and tastes good but has mild estery scent again! First time I didn't aerate enough and probably let fermentation get a little warm (maybe 72-74). This time I know I aerated pretty well and I got a stick-on thermometer, I know fermentation temp was always at most 70, closer to 67-68. Why on earth would the estery smell pop up, and pop up this late in fermentation? Also, the flavor was not particularly sweet (just a little sweet). Does a normal fermentation put off estery odors towards the end, even if the off flavor won't be there? Finally, is it better to check again to see if it's at the same gravity this weekend and bottle to avoid any chance of further off flavors, or better to let it sit an extra week or two and hope it falls out?

I know, I know, RDWHAHB - but I want to learn from this so batch 3 has no problems, or at least has a new, different problem

Using White Labs WLP-013

 

[Chowe]

You should keep fermentation in the low range for the yeast. WLP 013 needs 66F to 71F, higher temperatures will produce esters. Fermentation temp is usually 5 to 10 degrees over room temp as it produces heat.

 

[Teromous]

What does it actually smell like? "Esters" is a very broad description, and it might not even be esters that you are smelling.

 

[carvin160]

It's a mild banana smell. The last beer had a more-than-mild banana smell.

 

[carvin160]

Chowe, does that still hold even with the stick-on thermometer saying I was in the middle of the range, if briefly on the high side, but still below? I know ferment temp is going to be a bit higher than room, but I thought that was what the sticker was for!

Thanks!

 

[Chowe]

Those stick on thermometers don't give an accurate fermentation temp. I had the same problem with my first few batches, now I keep the fermentation temp in the low range and no more off flavors just great beer.

 

[Chowe]

Give those beers a few extra weeks or months to condition and the yeast will clean that banana taste and smell up.

 

[Teromous]

Well it's good that you mentioned banana because from my experience it has always been a temperature-dependent characteristic...also strain-dependent. I've used WLP013 before at a constant 65F without any noticeable esters at all. The only time I've gotten that type of flavor, is when I've specifically made a hefeweizen in the low 70's to high 60's.

 

[ajf]

Well, I wouldn't usually consider estery to be an off flavor. Most of my beers have a good dose of esters, because they are supposed to. Strangely, most of my beers use English yeasts, usually WLP002. English yeasts often produce esters (although WLP013 didn't produce any that I was aware of), but possibly you are more sensitive to esters than I am. Perhaps it does produce them, but I can't detect them.
How about trying WLP001, or S-05, or Nottingham. With good temperature control, they should all produce beers with very low levels of esters.

-a.

 

[RmikeVT]

Esters are not something that should develop after primary fermentation has taken place. Esters are formed during yeast reproduction and active yeast metabolism. That being said most esters are formed in the early stages of fermentation. As the beer "conditions", after primary fermentation, esters perception should gradually decrease.

Several things can lead to high level of esters. You've only addressed one, temperature. Fermenting at the high end or above the optimal yeast fermentation temp can result in an estery beer, there are other factors that can influence as well: 1) Pre-Ferment Oxygen levels, 2) Pitch Rate and 3) Yeast Genetics, 4) Free Nitrogen Level (I think this isn't a concern in all malt worts as barley malt has plenty of Free Nitrogen)

Are you using a thermometer you have confidence in to measure temps? I've sanitized a thermometer and taken temp readings during active fermentation, you only have to do once or twice to get an idea for the difference between the stick on therm and a well calibrated therm.

Are you Oxygenating your wort adequately?

Are you pitching enough viable/healthy yeast? Are you making a starter?

If you have addressed all of the above, maybe you need to choose a more neutral, forgiving strain. WLP001/1056/US-05, Nottingham, etc.

What also makes me nervous is that you are picking up an increase in esters after primary fermentation which could indicate infection. I've definitely had infections in my brews that took a trained palate of a BJCP judge to identify as an infection, everyone else thought I was fermenting too high or under pitching, etc. I tracked the infection down to a bucket I used and tossed it out and problems solved.

EDIT: After re-reading your post, you might want to relax and let the beer condition for an additional 2-4 weeks before getting nervous. 2 wk old beer vs 4 week old beer can be night and day.

 

[hunter_le five]

Well, I wouldn't usually consider estery to be an off flavor.

Depends on the style. An estery hefeweizen or saison might be desirable. An estery light lager might not be.

 

[Yooper]

EDIT: After re-reading your post, you might want to relax and let the beer condition for an additional 2-4 weeks before getting nervous. 2 wk old beer vs 4 week old beer can be night and day.

I'm pretty sure the beer is older than 2 weeks- it's been two and a half years since the OP posted. :cross:

Good info in your post, though- it should be very helpful for people tracking down estery off-flavors, especially during the heat of the summer.

 

[hunter_le five]

it's been two and a half years since the OP posted. :cross:

bahaha I didn't even catch that. holy necrothread batman!

 

[RmikeVT]

I'm pretty sure the beer is older than 2 weeks- it's been two and a half years since the OP posted. :cross:

Good info in your post, though- it should be very helpful for people tracking down estery off-flavors, especially during the heat of the summer.

How did I even dig that thread up? I thought I was looking through new threads. I bet esters and or beer are gone by now.