Author Topic: Ethyl acetate or fusels?  (Read 1294 times)

Offline Frosti2k2

  • 1st Kit
  • *
  • Posts: 4
    • View Profile
Ethyl acetate or fusels?
« on: March 25, 2017, 07:48:56 PM »
Hi all,

I have been experiencing a consistent issue with my brews. It is a solventy, hot taste that is very distracting. It is more noticeable when brewing high gravity beers and also when using belgian, saison or wheat yeasts, but I have also noticed it in more cleaner American or english strains.

From the faultfinding descriptions in 'how to brew' I have narrowed it down to either excessive ethyl acetate or fusel alcohols. The problem is I am not able to distinguish which one of these I am tasting.

Does anyone know any methods for distinguishing between the two? If I can identify it then I can start looking into my somewhat unorthodox processes etc. to see what might be causing it.

Cheers,
Matt

Offline Stevie

  • Official Poobah of No Life.
  • *
  • Posts: 6858
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #1 on: March 25, 2017, 07:58:18 PM »
Do you control your fermentation temps?

Offline HoosierBrew

  • Global Moderator
  • I must live here
  • *****
  • Posts: 13030
  • Indianapolis,IN
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #2 on: March 25, 2017, 07:58:51 PM »
Hi all,

I have been experiencing a consistent issue with my brews. It is a solventy, hot taste that is very distracting. It is more noticeable when brewing high gravity beers and also when using belgian, saison or wheat yeasts, but I have also noticed it in more cleaner American or english strains.

From the faultfinding descriptions in 'how to brew' I have narrowed it down to either excessive ethyl acetate or fusel alcohols. The problem is I am not able to distinguish which one of these I am tasting.

Does anyone know any methods for distinguishing between the two? If I can identify it then I can start looking into my somewhat unorthodox processes etc. to see what might be causing it.

Cheers,
Matt





Excessively high fermentation temps create hot, solventy fusels. Tell me how you ferment - do you use temp control for your fermentations?
Jon H.

Offline mabrungard

  • Brewmaster General
  • *******
  • Posts: 2377
  • Water matters!
    • View Profile
    • Bru'n Water
Re: Ethyl acetate or fusels?
« Reply #3 on: March 25, 2017, 08:19:57 PM »
Excessive oxygenation can also promote fusel production. In essence, anything that promotes high cell growth rate can produce fusels and esters. High fermentation temp does promote potentially high cell growth rates.
Martin B
Carmel, IN

BJCP National
Foam Blowers of Indiana (FBI)

Brewing Water Information at:
https://sites.google.com/site/brunwater/

Like Bru'n Water on Facebook
https://www.facebook.com/Brun-Water-464551136933908/?ref=bookmarks

Offline brewsumore

  • Brewmaster
  • *****
  • Posts: 623
  • Spokane, WA
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #4 on: March 25, 2017, 09:31:15 PM »
Yep, it's usually fusels due to too hot a pitch and/or ferment temp, especially within the first 0 - 48 hrs, and for many beginners might also involve poor yeast health from pitching less than the recommendable amount of yeast.  Some additional band-aid flavors can come from chlorine or chloramines in your tap water if brewing with that, which is simple to remove via one crushed campden tablet per 20 gal water, stirred in prior to heating the water.

Offline MJK

  • Cellarman
  • **
  • Posts: 34
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #5 on: March 25, 2017, 11:18:46 PM »
I bet if you give the high gravity/Belgian yeast a few months, the heat will go away any leave fruity/spicey flavor. It may be fusel, but time will change them to esters.
have fun

Offline Frosti2k2

  • 1st Kit
  • *
  • Posts: 4
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #6 on: March 26, 2017, 12:29:14 PM »
Anyway here is a run-down of my setup:

Equipment:      "Phil mill" grain mill, 50L stainless mash tun,  40L aluminium boil kettle/fermentor, copper pipe lauter manifold with silicone syphon hose, 10kW outdoor paella gas burner, corny kegging system, +other odds and ends.

Ingredients:      uncrushed grain and whole vacuum packed hops from 'the malt miller.com'. Dry yeast strains used for convenience  (liquid yeast used only a few times). Grain stored at room temp loosely closed bag, yeast packets in fridge, hops in freezer.

Water:      realised pretty quickly that portsmouth water is not really suitable for anything apart from Stout so I have been treating my tap water since I started. I use brun 'water spreadsheet calculator to determine phosphoric acid additions to both mash and sparge water and also add equal amounts of minerals to both waters depending on beer style. End goal is a room temp ph of about 5.5. Rarely this is checked with a ph meter but mostly assumed by the spreadsheet.

Process:     I have tended to attempt shortcuts in my all-grain process over the years. I started off brewing as described in 'how to brew' by John Palmer. Typical 3 vessel homebrew method of infusion mashtun ----> kettle ----> fermentor with rapid cooling to ferment temp using a copper immersion chiller. But for the last three years I have been using a cut down method in order to try and save time and simplify. This consisted of two mayor changes.... (1) I don't chill the wort after the boil.  (2) I do not rack to a fermentor. I ferment directly in the kettle.

So I would mash in the 50L pot for at least an hour, sometimes more, stirring about every 15mins. Then syphon into the boil kettle for a 60min rolling boil (90 for pilsner malt), with hops added as required. Protofloc/Irish moss tablet added last ten minutes.  Then I cover the pot with a few layers of cling film at flameout and then let cool for about 20 hours at room temp. Final temp adjustment before pitching yeast is done in a temperature controlled fridge. 
 I feel this method saves a lot of time but more importantly it guarantees an almost sterile wort and fermentor as it has been boiled for at least 60 mins.


For the dry yeast, I always rehydrate the packet using the manufacturers datasheet and use an online calculator to tell me how many grams of yeast are needed. I will then add the yeast, swirl the fermentor for a few minutes and after that I will add air using a medical syringe filter and a small aquarium pump for about 30 - 60 mins. Sometimes I will aerate with the pump first then add the yeast (30 mins) But sometimes I add the yeast first and just aerate longer  (60 minutes). My logic for this is that air can only saturate wort to about 8ppm so in half an hour the yeast will have taken up the 8ppm present and then by keeping the pump on there will be another 8ppm still in the wort when the pump is switched off after 60 mins. So the yeast will see a total of about 16ppm.

Then I would ferment at 17 - 20 deg C depending on the beer in the controlled fridge for 7-14 days. After day 4 I raise the temp about a degree a day until day 7 to increase yeast activity and then hold that temp until packaging into a corny keg and carbonated with a CO2 cylinder . Fermentation temperature is measured and controlled with a thermocouple stuck to the side of the fermentor with tape and a sponge over the top to insulate the sensor from the external influence. I'm told this gives an accurate beer temperature but I have never confirmed this by measuring directly inside the pot

Offline majorvices

  • Global Moderator
  • I must live here
  • *****
  • Posts: 9636
  • Polka. If its too loud you're too young.
    • View Profile
    • Yellowhammer Brewing Company
Re: Ethyl acetate or fusels?
« Reply #7 on: March 26, 2017, 01:04:43 PM »
If you are using filtered air you won't be over aerating. Doesn't sound like your issue is accelerated yeast growth unless you are monitoring ambient temp rather than temp in the beer. If you are fermenting at 20C ambient the temp of the fermenting beer may be closer to 22-24, which may be too warm for your yeast strain. Make sure you are monitoring the temp of the beer, not the ambient temp. The ambient temp may need to be closer to 15C.

Offline reverseapachemaster

  • Official Poobah of No Life.
  • *
  • Posts: 3144
    • View Profile
    • Brain Sparging on Brewing
Re: Ethyl acetate or fusels?
« Reply #8 on: March 26, 2017, 04:20:03 PM »
I also suspect it is a fermentation temperature issue.

I wonder whether the metal kettle is cooling more than the beer inside resulting in a significantly hotter fermentation than desired. On your next batch try taking temperature readings of the fermenting beer and compare it to the reading on your controller.
Heck yeah I blog about homebrewing: Brain Sparging on Brewing

Offline Frosti2k2

  • 1st Kit
  • *
  • Posts: 4
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #9 on: March 27, 2017, 09:12:13 AM »
That's a really good point regarding the ferment temperature. I'll definetely measure the delta between the probe that's taped onto the side of pot and a probe in the actual beer.  It's something I have wondered about for a long time but never confirmed.  I will report back after the next brew !  :)

Offline Stepp2

  • Cellarman
  • **
  • Posts: 25
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #10 on: March 27, 2017, 08:36:57 PM »
Excessive oxygenation can also promote fusel production. In essence, anything that promotes high cell growth rate can produce fusels and esters. High fermentation temp does promote potentially high cell growth rates.
This might be a question for a separate thread. Keep in mind I ask because I don't know. I've heard many brag about their yeast starting within 12 hrs and having aggressive fermentation as a good thing. How much O2 is to much?


Sent from my iPhone using Tapatalk

Offline MJK

  • Cellarman
  • **
  • Posts: 34
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #11 on: March 30, 2017, 01:02:52 AM »
HI Frosti,
What's the ABV?
I have had Belgians @ 10% that took 7months to mellow.
Also had 8% that took at least 4 months
Turned out phenomenal.

There is a quote by Vinnie Cilurzo (Russian River Brewing) from the book Brew Like a Monk(Stan Hieronymus).
"Belgian style ales cannot be treated like an IPA or Porter. They require more aging to round out their subtle flavors...."

Offline Frosti2k2

  • 1st Kit
  • *
  • Posts: 4
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #12 on: March 30, 2017, 08:06:49 PM »
My latest one is a 9% wheat beer fermented with two packs of danstar munich. I also used bottled low mineral water to eliminate any issues with my usual tap water/treatment.  It's two weeks in the bottle and it does have the solventy character but relatively mild. I've had much worse on 7% beers ! I could see this one conditioning out over time, but other beers I have made it was a severe off flavour that didn't seem to get any better with time

Offline MJK

  • Cellarman
  • **
  • Posts: 34
    • View Profile
Re: Ethyl acetate or fusels?
« Reply #13 on: April 06, 2017, 01:21:54 AM »
The process looks great. Not over aerated. Cool fermentation.
Its a head scratcher
You could try to overpitch. fusel are associate with growth.
Usually Belgians pitch at a low temp and let the beer free rise.
Don't know much about the particular yeast you have.

good luck