Co-pitching and ethyl acetate

[user 336313]

Hi, all.

This is my first post. I´m a professional brewer from the Netherlands. I brew at a medium sized brewpub. Ten tanks of ten hecto.

Recently I listened to a podcast about co-pitchting yeast. I was eager to try it on an all grain wee heavy. However, I might have botched it. I pitched a regular whole pack of S-04. That´s 500 grams. My idea was to co-pitch it with Abbaye Belgian yeast. But here is what I did: I only pitched four small packs of Abbaye. That´s 44 grams total. My reasoning was: let´s see if I can get a small influence of that Belgian yeast flavour. It fermented fine. But I just took a sample and noticed the nail polish remover smell of ethyl acetate. Now my hunch is this: the Abbaye yeast was only a small amount, and therefor got stressed out; it had to multiply way beyond it´s limit or capability, thus causing the unwanted esthers.

The beer has been in secondary fermenation for a couple of days now. There is a very slow, subtle stream of CO2 bubbles in the water lock, but it´s still going.

Thoughts? Is there a possibility that the ethyl acetate will become less prominent after conditioning? Because I´m not putting it in cans if it stays as noticable as this.

 

[jambop]

Don't get this a pro brewer comes on to a largely homebrewer site for advice ... why not ask you pro brewing chums? No offence but they will have far more to add than most on here who deal in much smaller volumes and have therefore much less experience of the problem you have encountered .
As a lemming
For my part as a homebrewer I doubt that the Abbaye would have stood a chance against the tenfold plus quantity of S- 04 which is well known to completely ferment out a wort inside 48 hrs and 500g into a 10hl FV would be just the right pitch. Ergo I doubt that the Abbey is responsible for your plight

 

[thehaze]

Hi there. What was the OG of the beer and how many liters ( aprox. ) were in the fermenter at the moment of pitch? I'm asking, as I have done 500-600 liters batches for the past 14 months or so, and have some experience with dry yeast pitching. I am gonna say that 544 gr. of yeast is an underpitch. For 1000 liters of beer with an OG of 1.065 / 16°P, you would need aprox. 750 gr. of yeast, at around 18°C. A bit less should you wish to increase ester formation. This is what I would personally use and have used before. Unfortunately, ethyl acetate will stick around in the beer and will not condition out. A friend of mine that brews lagers at a larger scale, had a recent batch where ethyl acetate was at high levels, and even after 55 days of condtioning, it didn't dissipate.

 

[user 336313]

Don't get this a pro brewer comes on to a largely homebrewer site for advice ... why not ask you pro brewing chums? No offence but they will have far more to add than most on here who deal in much smaller volumes and have therefore much less experience of the problem you have encountered .
As a lemming
For my part as a homebrewer I doubt that the Abbaye would have stood a chance against the tenfold plus quantity of S- 04 which is well known to completely ferment out a wort inside 48 hrs and 500g into a 10hl FV would be just the right pitch. Ergo I doubt that the Abbey is responsible for your plight

Hello Jambop,

Thank you for setting me straight. Sorry for being here ;-)
I´ve only been brewing professionally for 6 months and I´m still learning.
I will look for a forum for commercial brewers then.

As for your actual response to the subject... S-04 attenuates to 75%. It is possible the Abbaye is eating the remaining sugars. This would explain the super slow but long lasting secondary fermentation.

Anyway, thanks.

 

[dmtaylor]

You underpitched by about 50%. ALL of the yeast was stressed including the S-04. This batch cannot be salvaged. Next time use one 500 gram packet of each and you should have better results. Or if you are concerned about competition between yeasts, then ferment the two halves separately, then combine them after primary fermentations in both have been nearly completed.

 

[user 336313]

Hi there. What was the OG of the beer and how many liters ( aprox. ) were in the fermenter at the moment of pitch? I'm asking, as I have done 500-600 liters batches for the past 14 months or so, and have some experience with dry yeast pitching. I am gonna say that 544 gr. of yeast is an underpitch. For 1000 liters of beer with an OG of 1.065 / 16°P, you would need aprox. 750 gr. of yeast, at around 18°C. A bit less should you wish to increase ester formation. This is what I would personally use and have used before. Unfortunately, ethyl acetate will stick around in the beer and will not condition out. A friend of mine that brews lagers at a larger scale, had a recent batch where ethyl acetate was at high levels, and even after 55 days of condtioning, it didn't dissipate.

SG was 1,076
1000 liters total.
Underpitching sounds plausible, however I learned to brew on these same kettles and have been pitching 500 grams fpr EVERY brew so far. According to the previous brewer/ current owner this was fine. And it HAS been fine for most brews...

 

[user 336313]

You underpitched by about 50%. ALL of the yeast was stressed including the S-04. This batch cannot be salvaged. Next time use one 500 gram packet of each and you should have better results. Or if you are concerned about competition between yeasts, then ferment the two halves separately, then combine them after primary fermentations in both have been nearly completed.

I would say you´re right! And you very well might be. However I learned to brew on these same kettles and have been pitching 500 grams for EVERY brew so far. According to the previous brewer/ current owner this is fine. And it HAS been fine for most brews... Obviously now I´m starting to doubt it...

 

[dmtaylor]

It depends so much on the original gravity though. Most batches might be 1.050 to 1.065 or so. This one was 1.076 which indicates to most brewers that you really need to pitch a much bigger amount.

 

[user 336313]

It depends so much on the original gravity though. Most batches might be 1.050 to 1.065 or so. This one was 1.076 which indicates to most brewers that you really need to pitch a much bigger amount.

Yeah, and looking at the total cost of a recipe like that one more pack of yeast isn´t really a reason not to.
Still odd that our other high gravity beers usually turn out okay... This is a new recipe though...
Anyway, thanks man.

 

[jambop]

SG was 1,076
1000 liters total.
Underpitching sounds plausible, however I learned to brew on these same kettles and have been pitching 500 grams fpr EVERY brew so far. According to the previous brewer/ current owner this was fine. And it HAS been fine for most brews...

First thing right off I am not saying you should not come here because you are a pro brewer BUT I am surprised that as a pro brewer you did not seek the advice of another pro brewer first and thus get totally sound advice base on professionally gained experience and not a bunch maybe this maybe that . Although I am not saying you will not get well meaning advice on this site ... possible from a pro brewer too.
however...
Even according to Fermentis you are not far off for pitching rate. Their minimum pitch rate is 50g per hectolitre so you are not wildly out of spec but as I say I am not a pro brewer that may be enough given your OG . I doubt that Abbaye has anything at all to do with the problem because S-04 has more or less the same attenuation 74 to 84 % again that is just an opinion. Is there a possibility you had some other fermenting condition slightly out... temp for example or has there been an infection of some sort? The other day someone on here posted an article wherein the writer stated that dried yeasts is in his experience actually has well over pitched in terms of cell count required for a healthy fermentation ... he apparently wrote the book on yeast... whatever that means BUT if what he says is remotely true your pitch rate would not be at fault.
Anyway one way or another you may have learned something but I still think you need expert advice to ensure you do not have a repeat occurrence.

 

[user 336313]

First thing right off I am not saying you should not come here because you are a pro brewer BUT I am surprised that as a pro brewer you did not seek the advice of another pro brewer first and thus get totally sound advice base on professionally gained experience and not a bunch maybe this maybe that . Although I am not saying you will not get well meaning advice on this site ... possible from a pro brewer too.
however...
Even according to Fermentis you are not far off for pitching rate. Their minimum pitch rate is 50g per hectolitre so you are not wildly out of spec but as I say I am not a pro brewer that may be enough given your OG . I doubt that Abbaye has anything at all to do with the problem because S-04 has more or less the same attenuation 74 to 84 % again that is just an opinion. Is there a possibility you had some other fermenting condition slightly out... temp for example or has there been an infection of some sort? The other day someone on here posted an article wherein the writer stated that dried yeasts is in his experience actually has well over pitched in terms of cell count required for a healthy fermentation ... he apparently wrote the book on yeast... whatever that means BUT if what he says is remotely true your pitch rate would not be at fault.
Anyway one way or another you may have learned something but I still think you need expert advice to ensure you do not have a repeat occurrence.

Temperature was good all through-out fermentation. Low end of the range. Next batch I'll do with two packs of S-04. Still have an off feeling about the Abbaye, though. Anyhow, it will suck to flush this batch down the drain... Thanks for replying!

 

[jambop]

Temperature was good all through-out fermentation. Low end of the range. Next batch I'll do with two packs of S-04. Still have an off feeling about the Abbaye, though. Anyhow, it will suck to flush this batch down the drain... Thanks for replying!

Well that is fine just remember to increase the price of your beer by about 6 cents per litre

 

[Willammes Macena]

Olá Jambop,

Obrigado por me esclarecer. Desculpe por estar aqui ;-)

Vou procurar um fórum para cervejeiros comerciais então.

Aprecie a hospitalidade do Tio San

Enjoy Uncle San's Hospitality

 

[thehaze]

SG was 1,076
1000 liters total.
Underpitching sounds plausible, however I learned to brew on these same kettles and have been pitching 500 grams fpr EVERY brew so far. According to the previous brewer/ current owner this was fine. And it HAS been fine for most brews...

Thank you for the reply. I will stick with my initial thought and say you underpitched. Even if fermented warm, you would still have to use around 800-850 gr., which makes for quite a difference. I agree however that sometimes, 500 gr. can work for 10 HL, and it would/could be fine. Personally, I don't like to risk it, especially when brewing smaller batches, which are more expensive due to the size of these (* when compared to really large batches, where ingredients are bought in bulk ).

I am a big fan of matching yeast and wort, gram for liter, when the original gravity exceeds 15-16°P. Anything lower can work work with 0.4-0.8 gr./liter. Beers that exceed 15-16°P ( at least for me ), are usually IPAs, which are expensive due to the amount of hops, Stouts or anything malt-heavy and complex, where I want a clean fermentation, as these will condition and keep longer than IPAs.

Regarding the beer itself: are you sure that it's acetone/solvent/ethyl acetate you are smelling and tasting, and not a slight yeast character from the Abbaye yeast? Lallemand Abbaye does produce phenols, and some of these might be perceived differently by people. Although I am aware that 44 gr. is such a small amount, that the yeast itself might've not had the chance to multiply/express itself, I thought I should mention it.

Should you have an empty tank/fermenter that you do not use, transfer the beer there and keep it, or maybe just a few liters, and see how it evolves with time. Cheers!

 

[user 336313]

Thank you for the reply. I will stick with my initial thought and say you underpitched. Even if fermented warm, you would still have to use around 800-850 gr., which makes for quite a difference. I agree however that sometimes, 500 gr. can work for 10 HL, and it would/could be fine. Personally, I don't like to risk it, especially when brewing smaller batches, which are more expensive due to the size of these (* when compared to really large batches, where ingredients are bought in bulk ).

I am a big fan of matching yeast and wort, gram for liter, when the original gravity exceeds 15-16°P. Anything lower can work work with 0.4-0.8 gr./liter. Beers that exceed 15-16°P ( at least for me ), are usually IPAs, which are expensive due to the amount of hops, Stouts or anything malt-heavy and complex, where I want a clean fermentation, as these will condition and keep longer than IPAs.

Regarding the beer itself: are you sure that it's acetone/solvent/ethyl acetate you are smelling and tasting, and not a slight yeast character from the Abbaye yeast? Lallemand Abbaye does produce phenols, and some of these might be perceived differently by people. Although I am aware that 44 gr. is such a small amount, that the yeast itself might've not had the chance to multiply/express itself, I thought I should mention it.

Should you have an empty tank/fermenter that you do not use, transfer the beer there and keep it, or maybe just a few liters, and see how it evolves with time. Cheers!

Thank you. I've been away for a week. In the meantime it's been conditioning. I'll sip from a sample on Monday and will take you up on your advice next batch.