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English yeasts and the miracle ester sweet spot of generation nr X

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beervoid

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Errr - where do you get the idea that they're adding so much yeast that it affects the amount of trub they see? I certainly didn't say that - SanPancho was trying to explain their process by claiming that it was driven by reducing trub, I pointed out that they had gone the other way, from no yeast as yeast food to some yeast. Even one yeast cell introduced as yeast food would counter SanPancho's point as it would technically represent an increase in trub - but it certainly wouldn't be visible!

They're not doing it as a flavour thing, it's just a free way to feed the yeast using material that would otherwise go to waste.



See above - they're not doing anything special with the yeast, certainly not loading it with zinc. It's just recycled waste.

Anyway, this is all rather off-topic to beervoid's original point, which was about the effect of yeast generation on its character. It seems to be a recognised thing that Conan take a generation or two to get into its stride - not as much as five though. John Kimmich claims to be able to recognise what generation Heady Topper has been made with when tasting blind, and I get the impression that they blend batches to smooth out the differences. But then once you get past 10-12 generations it gets into a cycle where the desired characters fade in and out. You can imagine genetic mechanisms for how that happens, but I think for now you just accept that it's how it seems to behave.
I have heard that from Kimmich as well hence I opened this thread.
On another note, I've had the same thing happen to me with a later generation of wy1318 london III.
 

mediant

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the strangeness is compounded when you're talking about a recipe for a dipa, which is one of the beers that has some of the highest losses to trub/hops/yeast/etc. adding more mass -- that soaks up beer-- than necessary seems odd to me.
If the rate is any close to that of Servomyces (1g dry per 100 liters), then there shouldn't be any loss to speak of.
zinc and leucine (typically found in nutrient blends) have positive correlation with ester production.
AFAIK leucine selectively stimulates Isoamyl acetate ester (banana, which is welcome is certain styles only), while valine stimulates Isobutyl acetate production (fruity, seems more appropriate in IPAs). But then, if they only add 260g of valine, it makes about 100mg/l (assuming their batch is 2,500 liters), which is only enough for treating VDK, as per https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3708283/
 

SanPancho

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Maybe. Maybe not. Maybe they do it for another reason. Without getting the answer directly from the source its a bit of a guessing game. Could be something in their water, grist, mash, brewhouse, yeast harvest/propagation, cellar, etc etc. Too many variables to just guess. You really need to understand the big picture.

However there are many research papers on ester production, and if that is what you are after id get ideas there and follow them to a method that works for you. Higher end in the yeasts temp range, nutrients, less o2, no spunding, and a downwards temp/time slope are all associated with ester production. There are others, those are the basic ones.
 

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servomyces is dry product that dissolves in wort. There is essentially no trub at all. Dead yeast? Not the same.

I noted leucine as thats the first paper that came to mind and as i recall they used s04, which seemed appropriate here. There was no claim that its the one responsible for flavors OP is chasing. Simply a statement that ester production can be increased by adding nutrients. May not be “historical “ but it still works.
 

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Zinc is added for cell reproduction - that’s the only thing we add in respect to yeast health. I doubt that zinc in and of itself is responsible for ester production - I could see a case for arguing a lack of zinc could cause off flavours, due to unhealthy/underpitched yeast.
 
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If they throw old yeast in the whirlpool wouldn't it mimick reusing an older generation?
As older generations will contain more and more dead yeast.

So the question is, does the old yeast provide nutrition for more ester production or does the yeast mutate by generation 6?
Which is consequently about where I started noticing increased ester production 3x in a row now. 2x times with Conan 1x with London Ale III.
I just found this all so coincidental.
 

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If they throw old yeast in the whirlpool wouldn't it mimick reusing an older generation?
I don't really think it would. The reason being that old yeast thrown into the whirlpool gets cooked and thus reduced to its constituent compounds whereas yeast that you pitch into cold wort even if dead will take a (hopefully) long time to autolise and will therefore mostly be unavailable as a nutritional source for the live yeast as yeast, unlike some amoebae, is devoid of any digestive system and cannot cannibalize whole cells.
 

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have I heard of folks doing it? yes, of course. but only brewers that I might affectionally refer to as "old timers"...I have no idea who these people are or any of their beers or any of their histories- brewery or recipes.
If you've not heard of Cloudwater, here's some context - this is a good introduction for USians, here's a longer interview. They're certainly not old-timers!

Don't get hung up on the trub aspect of old yeast, it's minimal in this context.

Cloudwater are obsessed with minimising VDKs - one of them is super-taster of diacetyl, which is why they use ALDC and valine to respectively destroy a precursor and minimise its production in the first place. ALDC or valine on their own are only partially effective, which is why it's worth using both together.
 
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beervoid

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If you've not heard of Cloudwater, here's some context - this is a good introduction for USians, here's a longer interview. They're certainly not old-timers!

Don't get hung up on the trub aspect of old yeast, it's minimal in this context.

Cloudwater are obsessed with minimising VDKs - one of them is super-taster of diacetyl, which is why they use ALDC and valine to respectively destroy a precursor and minimise its production in the first place. ALDC or valine on their own are only partially effective, which is why it's worth using both together.
Had the pleasure to drink some of their beers, they are up there with the rest Tree House, Trillium, Other Half etc..

Do you know by any chance what the
Collect 15c
Trim 17c
temperatures stand for on their sheet?
 

Northern_Brewer

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Wort is "collected" in the FV - so they're transferring to the FV at 15C, and then "trimming" (ie adjusting) the temperature to 17C. They've gone into more detail on their fermention profiles in some of their blogs, it was discussed a bit at the time over on the main NEIPA thread, which is perhaps a more appropriate place for it?
 

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I think the takeaway from cloudwater is practice providing as ideal an environment for the yeast as you can....keep it as healthy as possible.

Esters will follow.
 
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beervoid

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Wort is "collected" in the FV - so they're transferring to the FV at 15C, and then "trimming" (ie adjusting) the temperature to 17C. They've gone into more detail on their fermention profiles in some of their blogs, it was discussed a bit at the time over on the main NEIPA thread, which is perhaps a more appropriate place for it?
I would say the esters I got from conan are very similar to Cloudwater, I think they are using the same or related strains. I dont start fermentation that low though but my fermentation is similar.
 
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Northern_Brewer

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I would say the esters I got from conan are very similar to Cloudwater, I think they are using the same or related strains.
They are generally pretty open about what yeast they use, mostly it's one or other Conan for their hoppy stuff. Used to be a mix of WLP095 and WLP4000, then they tended to use more 4000, most recently they seem to have mostly been using Lallemand's version. They do mix it up thought - for instance they did some DIPAs with the Lees yeast which is pretty typical of the multistrains used by British regionals - it's been repitched for nearly 5000 generations. That only works if you have a multistrain to give the resilience that is missing from the single strains typically sold by the homebrew labs.
 
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I've decided to mail the yeast manufacturer on this matter to see if they could shed some light. They say it's very unlikely this is from a genetic shift and speculate it's probably that because of the older generations loosing viability over time i'm under-pitching at a point I get more esters as the yeast has to replicate much more.
 

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Good research.

Will you knowingly underpitch now?

And are the flavors/aromas from those 4th/5th generations amplified versions of the healthy versions esters or different esters?
 
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beervoid

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Good research.

Will you knowingly underpitch now?

And are the flavors/aromas from those 4th/5th generations amplified versions of the healthy versions esters or different esters?
I will be experimenting but the problem is I have no way to count yeast. I'll try to pitch less with a new package probably.
Amplified esters I would say describe most accurately. I always make 10gallon split in 2 batches to experiment.
I usually have a hard time picking up differences in yeast when I test different yeasts but with this batch it was obvious which one is conan.
 

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Very interesting data. I am not surprised to see CW increase their pitch rate/zinc levels over the course of the brews, as the flavor and stability issues that come with a stressed fermentation are not worth the possible increase in esters. There are other means of increasing fruity esters that does not affect yeast health and beer quality. Their use of acetolactate and valine is interesting though. It is nice to see they are adding zinc in the FV and not in the boil as is mostly the case; most of the zinc gets bound in the trub and the yeast see little benefit from available zinc in fermentation.

I still find the 24g/L dry hop completely absurd and contrary to achieving good hop aroma. Whatever works for them.
 
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Very interesting data. I am not surprised to see CW increase their pitch rate/zinc levels over the course of the brews, as the flavor and stability issues that come with a stressed fermentation are not worth the possible increase in esters. There are other means of increasing fruity esters that does not affect yeast health and beer quality. Their use of acetolactate and valine is interesting though. It is nice to see they are adding zinc in the FV and not in the boil as is mostly the case; most of the zinc gets bound in the trub and the yeast see little benefit from available zinc in fermentation.

I still find the 24g/L dry hop completely absurd and contrary to achieving good hop aroma. Whatever works for them.
I just had a 24g/l dipa from them. It had a slight hopburn and a in my opinion muddled hop character.
Please do elaborate on the other means of increasing fruity esters.
 
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beervoid

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Coming back to yeast pitching rates of CW if that is 240millon cells per ml
I calculated it back to 456 billion cells per 5 gallons that seems like a huge over-pitch.
I'm sure I'm doing something wrong.
If I use a yeast calculator the nr goes up tp 800+ billion..
Not sure how to read this spreadsheet
 
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beervoid

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Seems both under and over pitching can stimulate ester production. Gotta love brewing!

""When a cell is budding without enough oxygen, is when esters are produced.". Perhaps this could be the cause of the commonly held misconception that underpitching increases ester production? Underpitching promotes growth, which starts as aerobic growth (aerobic metabolic pathways are preferred over anaerobic ones) which consumes oxygen, thus forcing the yeast into budding without oxygen and producing esters. If underpitched beers are also under-oxygenated (which seems a plausible scenario) this could create the impression that underpitching results in estery beers. "

"
To complicate things even more... There is also evidence that heavy "over pitching" of yeast will produce similar higher esters to heavy "under pitching". The rational seems to be that fermentation finishes with less reproduction and a lower number of yeast generations. These earlier generations create more esters due to reduced energy toward reproduction, and are born into a higher sugar environment so they tend to flocculate in mass post fermentation rather than stay in suspension and clean up some remaining esters.

Plenty of disagreement out there over whether over pitching causes a beer to be cleaner or have more esters. My guess is that it is somewhat strain dependent."

Taken from: https://homebrew.stackexchange.com/questions/22989/pitching-rates-and-ester-formation
 

Vale71

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Please do elaborate on the other means of increasing fruity esters.
Fermenter geometry is really important. Cylindroconical fermenters are the worst (if esters is what you aim for, that is). Shallow, large, square fermenters are best at promoting esters. Some old breweries haven't changed their fermenter geometry since forever for that very reason, even if they probably had to line them with stainless steel and cap them to prevent CO2 intoxication of the workforce due to updated health and safety regulations.
 
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beervoid

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Fermenter geometry is really important. Cylindroconical fermenters are the worst (if esters is what you aim for, that is). Shallow, large, square fermenters are best at promoting esters. Some old breweries haven't changed their fermenter geometry since forever for that very reason, even if they probably had to line them with stainless steel and cap them to prevent CO2 intoxication of the workforce due to updated health and safety regulations.
I ferment in corny kegs and had great esters so this doesnt seem to be the case here at least for the yeast I use.
 

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Fermenter geometry is really important. Cylindroconical fermenters are the worst (if esters is what you aim for, that is). Shallow, large, square fermenters are best at promoting esters. Some old breweries haven't changed their fermenter geometry since forever for that very reason, even if they probably had to line them with stainless steel and cap them to prevent CO2 intoxication of the workforce due to updated health and safety regulations.
Why is that so?
 

bierhaus15

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Can you elaborate on this?
Here is the spitballing, top of my head list of stuff for impacting esters (+/-). Basically all the stuff I had to memorize from Greg Casey's work. Look it up.

Yeast strain dependent - BAP2 gene and leucine uptake (+)
Ferment temp, higher (+) --> increasing temp towards end of fermentation with yeast flocculation (some yeasts) (+)
Pitch rate, lower (+)
Oygenation, higher (-)
Fermentation rousing (-)
High FAN/low unsaturated lipids (+) --> increase esters by addition of glucose or rice/sugar
Low FAN/high lipids (-) --> typical all malt worts (especially Euro malts)
Increased trub in fermentation (-)
Zinc (+)
Serial repitching (-)
Pitching in turbid wort (-)
Fermentation pressure (-)
High gravity wort (+) --> ethyl acetate
High maltose fermentations (-)
Undermodified malts (+)
High caramel malts (-)
Fermentation geometry

And my favorite two bits; propagating yeast in wort media high in glucose/fructose can increase ester development in subsequent generations. Also, "yeast are not indifferent to design and process change".... if a yeast is accustomed to a particular fermenter geometry/process and is then transferred to another fermentation environment, it will not behave the same nor produce the same fermentation flavor. Pretty much explains why all UK home brew strains never taste the same as the original, among other reasons. I worked at a brewery that went from shallow box fermenters to CCVs and flavor matching ale fermentations between the systems was nearly impossible. Courage struggled with this mightily for years.

Edit: Obviously, not all of these are better for total flavor quality.
 

Northern_Brewer

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When thinking about pitch rate, it's not just about the esters produced by the yeast - although underpitching can have a dramatic effect - see this for the effect of underpitching US-05 on isoamyl acetate and ethyl hexanoate.

But on the following slide you'll see the effect of pitching on hop compounds - overpitching gives a particularly dramatic increase in geranyl isobutanoate and to a lesser extent myrcene and citronellol, but a decline in methyl geranate.
 
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beervoid

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When thinking about pitch rate, it's not just about the esters produced by the yeast - although underpitching can have a dramatic effect - see this for the effect of underpitching US-05 on isoamyl acetate and ethyl hexanoate.

But on the following slide you'll see the effect of pitching on hop compounds - overpitching gives a particularly dramatic increase in geranyl isobutanoate and to a lesser extent myrcene and citronellol, but a decline in methyl geranate.
Thanks for sharing that, fascinating stuff... was that from an australian conference?
I guess Methyl Geranate is Geraniol derived?

My next brew experiment has got to be an under-pitch vs over pitch now...
 
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