Ethyl acetate or fusels?

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frosti2k2

Ethyl acetate or fusels?

Post by frosti2k2 » Sat Mar 25, 2017 7:24 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

Fil
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Re: Ethyl acetate or fusels?

Post by Fil » Sat Mar 25, 2017 10:11 pm

I would be inclined to suggest fermentation temperature and or fluctuations are probably at the root.

a very general rule of thumb with yeasts to get the best or cleanest flavour from them is to ferment at the lower end of the comfort range suggested.

keeping the temperature stable will also help a brewfridge is the ideal solution however insulating the fv from the variances in daily temps can also help. And if you need cheap chilling options the most basic solutions involve sitting in a cold water bath or wrapping with insulation and introducing frozen 4pint milk bottles of water or similar and exchanging daily or when necessary.
ist update for months n months..
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Re: Ethyl acetate or fusels?

Post by Mashman » Sun Mar 26, 2017 8:24 am

I agree, sounds a like temperature issue, but what are your somewhat unorthodox processes....?
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frosti2k2

Re: Ethyl acetate or fusels?

Post by frosti2k2 » Sun Mar 26, 2017 1:31 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

frosti2k2

Re: Ethyl acetate or fusels?

Post by frosti2k2 » Sun Mar 26, 2017 1:33 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

McMullan

Re: Ethyl acetate or fusels?

Post by McMullan » Sun Mar 26, 2017 2:36 pm

I think that is what 'hooch' is supposed to be like. Stop cutting corners :lol:

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Re: Ethyl acetate or fusels?

Post by Fil » Sun Mar 26, 2017 3:51 pm

its the temp rising upto 27C thats probably at the root of your issue, while a diactyl rest or slight rise in fv temp at the end of primary upto the top range of the yeast comforts temperature zone and when your a few points off your target FG can aid in the final 'clear up of residual fermentables, a daily rise in temp over 7-10days may well raise the temp into easter and fussel generating temps when you have too many sugars available still.

I would also consider changing the method to incorporate a clean FV, or at least bag, sock, or spider the hops so your not fermenting on decomposing hop matter for a fortnight. thats not a common brewday practice..

By all means brew Your way, but temper it a bit too..
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

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Re: Ethyl acetate or fusels?

Post by jaroporter » Sun Mar 26, 2017 4:41 pm

i read that as a temperature increase for only three days, so maybe 23C max? but i agree it sounds like the temperature is not as controlled as you'd like. maybe check the accuracy of the thermocouple.
i don't see anything that unorthodox that would cause those flavours, it all screams fermentation is wrong. maybe chuck a thermometer in the wort regularly over the first 24hrs. my only guess based on that info would be over-aeration causing the yeast to ferment too crazily at the start. i've had that problem when overpitching yeast slurry and the fermentation fridge hasn't been able to keep up.
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Re: Ethyl acetate or fusels?

Post by orlando » Mon Mar 27, 2017 8:47 am

There is a couple of points not raised so far that I would address, regardless of whether they are at fault. The first is using phosphoric acid for your alkalinity reduction. I suspect that my use of this was influenced by American brewers (Gordon Strong springs to mind). It is championed because of its "neutrality", but I found I would get a lot of white sludge in the bottom of my HLT. Conversations with British brewers revealed that a lot of this is calcium. This is a very important water component for all beers but one that needs to be high in British styles. I now use sulphuric and or hydrochloric depending upon the style. This may not be the problem but it is an issue to address. I was also struck by your method after the boil, by not chilling and leaving in the kettle it is possible that DMS is starting to reform, is it possible it is this you are smelling and tasting. Have you considered the no-chill cube method? I wonder also whether your aeration method is at fault too. Although there is some debate over aeration before or after pitching, received wisdom is aeration first, I always do and it always works. I have moved to pure O2, which I accept is a little unusual and for good reasons, but it does eliminate the problem of airborne infection. You're right about the limits of alternative methods to affect O2 uptake but I'm not convinced that 60 minutes using your method is advisable or that it would get you to 16ppm.

Before I started reading your methods I had fermentation temperature as the key to the problem, but assuming you do exactly what you say and are absolutely sure it doesn't rise above the manufacturers recommended range it can't be that. The higher gravity and "continental" yeasts you mention made me think of another possible "fault" you are detecting. Is it a phenolic smell and taste that you are experiencing, if so this makes it all a slightly different set of problems?
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Re: Ethyl acetate or fusels?

Post by AnthonyUK » Mon Mar 27, 2017 9:47 am

What is the condition of the ferment when you start to raise the temp? WIth some yeasts depending on quantity and quality the ferment can be pretty much complete where with others it is just getting going. I would only raise the temp once you are sure the vigourous phase is complete and the yeast just need a little assistance in completing the task.

With a large quantity of healthy yeast you can afford to ferment at higher temps without major issues.

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Re: Ethyl acetate or fusels?

Post by rpt » Mon Mar 27, 2017 5:59 pm

You don't need to aerate wort if you are using dry yeast so I'd eliminate that step. I'd also suggest a no-chill cube. You can then ensure your FV is clean and sterile.

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orlando
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Re: Ethyl acetate or fusels?

Post by orlando » Tue Mar 28, 2017 7:14 am

rpt wrote:You don't need to aerate wort if you are using dry yeast so I'd eliminate that step.
The OP mentions high gravity beers, some dry yeast manufacturers would agree that in the case of these beers extra oxygen can be required. The technique of getting it in is a possible source of the problem, particularly if underpitched. Like you I think the FV sounds like this particular problem.
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Conditioning:
Drinking: Southwold Again,

Up Next: John Barleycorn (Barley Wine)
Planning: Winter drinking Beer

frosti2k2

Re: Ethyl acetate or fusels?

Post by frosti2k2 » Thu Mar 30, 2017 9:15 pm

I would usually wait until day 4 to start raising the temp and i would only raise it a maximum of 3deg C above the fermentation temp. Usually by day 4 I can see the krausen has mainly dropped and I cannot hear much activity inside the pot (clingfilm lid helps me hear the activity).

As for the water, my latest brew used bottled low mineral water to eliminate any issues with my usual tap water / treatment. The beer does show the solventy taste to a moderate degree

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Re: Ethyl acetate or fusels?

Post by orlando » Fri Mar 31, 2017 6:58 am

frosti2k2 wrote:I would usually wait until day 4 to start raising the temp and i would only raise it a maximum of 3deg C above the fermentation temp. Usually by day 4 I can see the krausen has mainly dropped and I cannot hear much activity inside the pot (clingfilm lid helps me hear the activity).

As for the water, my latest brew used bottled low mineral water to eliminate any issues with my usual tap water / treatment. The beer does show the solventy taste to a moderate degree
Do you not make this decision based on gravity? I wonder whether you are deciding this on days elapsed rather than a hydrometer, it could be your raising temp too early. Do you raise the temp all in one go or incrementally?
I am "The Little Red Brooster"

Fermenting:
Conditioning:
Drinking: Southwold Again,

Up Next: John Barleycorn (Barley Wine)
Planning: Winter drinking Beer

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