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View Full Version : Yeast's "awkward phase"



Trenchie
02-14-2017, 10:32 PM
Hello Meaders,

i've looked around to find a yeasts life is in phases, and nutrients are time and/or sugar break scheduled. yeast phases are the lag, growth(accelerate,decelerate), ferment and stationary. nutrients are 24, 48, 72, and 168 hours or 1/3 sugar break (I'm thinking SP should govern these additions more than time but i'm still a nooby).

I have two 3 gallon "traditional" batches nearing the end of ferementation, one now SP1.002 (OG1.088) and the other SP1.025 (OG1.102)

so ... what happens with the yeast beyond the "fermentation phase" (3-30days?) and even beyond the "stationary phase"?

I guess I want to understand why to rack (or cold crash or add more chemistry) and not just let the batch sit and "age" for a few months?

will the yeast die eventually or continue to ferment in ever decreasing %'s indefinitly (or until I personally filter them)?

and how could that (letting it sit without racking) effect the quality of my product?

caduseus
02-14-2017, 11:12 PM
please consider buying The Compleat Meadmaker by Ken Schramm.
this will answer these questions and more

Squatchy
02-15-2017, 12:44 AM
Hello Meaders,

i've looked around to find a yeasts life is in phases, and nutrients are time and/or sugar break scheduled. yeast phases are the lag, growth(accelerate,decelerate), ferment and stationary. nutrients are 24, 48, 72, and 168 hours or 1/3 sugar break (I'm thinking SP should govern these additions more than time but i'm still a nooby). So there are only 3 phases. Lag, Exponential growth phase and stationary phase. Most of all your flavor is made during the growth phase. The longer you keep your must in the growth phase the more esters you gain and the stronger your biomass will become. I keep my batch considerably cooler during this time than I will once we move into stationary.

I have two 3 gallon "traditional" batches nearing the end of ferementation, one now SP1.002 (OG1.088) and the other SP1.025 (OG1.102) WHat is SP? We call this FG * Final gravity

so ... what happens with the yeast beyond the "fermentation phase" (3-30days?) and even beyond the "stationary phase"? You should keep the yeast roused (stirred up in suspension) the entire time yeast are in your vessel. Until you finally want them to drop because you want to rack.

I guess I want to understand why to rack (or cold crash or add more chemistry) and not just let the batch sit and "age" for a few months? You do want to age with the yeast in suspension. The longer the better. They will eat up some of the left over chemicals they made during fermentation. This then will make your flavor profile cleaner. The longer they are in there will cause them to drop much faster once you decide to do this. The only time I would suggest racking off the lees as soon as your ferment is over is if you have had any sulpherish smells. If so then rack as soon as your ferment is over.

will the yeast die eventually or continue to ferment in ever decreasing %'s indefinitly (or until I personally filter them)? Over time they will die. They can only make alcohol as long as there is sugar to convert into ethanol. Or until their alcohol tolerance has been reached. Even if they stop assimilating ethanol because they hit their top end they still don't die right away. They just stop making ethanol. At least for a while. I have many times had a yeast tap out. If you add water or fruit juice into this state the water or fruit will lower the ABV and they will go back to work. I don't know for sure how long they can hang out at that ABV level before they die of Alcohol poisoning.

and how could that (letting it sit without racking) effect the quality of my product? I already answered this in the above. It will make your final product drinkable faster for sure. And your lees will be more compact. (or at least it drops out and clears faster)


Welcome to the forums

Trenchie
02-15-2017, 03:51 PM
Thanks Squatchy, i've also got the caduseus suggestion on order.

as for stirring ... I thought that was a no-no after so many days, I figured once in the stationary phase. the stirring would introduce O2 and cuase flavor issues. and/or that stirring was used for degassing that would benefit bottling (no flying corks). is stirring something more subjective or opinionated and how does my waiting to rack influnce the stir?

thanks

PS: and yes, I did miss the acronym, I should have type OG, SG and FG.

Stasis
02-15-2017, 04:52 PM
that was a confusing post by squatchy. I skimmed over it a couple of times and never realized the quote included squatchy's input as well. I thought he was referring to a post that was deleted or another thread somewhere else

Trenchie
02-15-2017, 05:56 PM
here's the conversation visually altered for the Q-A

i've looked around to find a yeasts life is in phases, and nutrients are time and/or sugar break scheduled. yeast phases are the lag, growth(accelerate,decelerate), ferment and stationary. nutrients are 24, 48, 72, and 168 hours or 1/3 sugar break (I'm thinking SP should govern these additions more than time but i'm still a nooby). So there are only 3 phases. Lag, Exponential growth phase and stationary phase. Most of all your flavor is made during the growth phase. The longer you keep your must in the growth phase the more esters you gain and the stronger your biomass will become. I keep my batch considerably cooler during this time than I will once we move into stationary.

I have two 3 gallon "traditional" batches nearing the end of ferementation, one now SP1.002 (OG1.08 and the other SP1.025 (OG1.102) WHat is SP? We call this FG * Final gravity

so ... what happens with the yeast beyond the "fermentation phase" (3-30days?) and even beyond the "stationary phase"? You should keep the yeast roused (stirred up in suspension) the entire time yeast are in your vessel. Until you finally want them to drop because you want to rack.

I guess I want to understand why to rack (or cold crash or add more chemistry) and not just let the batch sit and "age" for a few months? You do want to age with the yeast in suspension. The longer the better. They will eat up some of the left over chemicals they made during fermentation. This then will make your flavor profile cleaner. The longer they are in there will cause them to drop much faster once you decide to do this. The only time I would suggest racking off the lees as soon as your ferment is over is if you have had any sulpherish smells. If so then rack as soon as your ferment is over.

will the yeast die eventually or continue to ferment in ever decreasing %'s indefinitly (or until I personally filter them)? Over time they will die. They can only make alcohol as long as there is sugar to convert into ethanol. Or until their alcohol tolerance has been reached. Even if they stop assimilating ethanol because they hit their top end they still don't die right away. They just stop making ethanol. At least for a while. I have many times had a yeast tap out. If you add water or fruit juice into this state the water or fruit will lower the ABV and they will go back to work. I don't know for sure how long they can hang out at that ABV level before they die of Alcohol poisoning.

and how could that (letting it sit without racking) effect the quality of my product?
I already answered this in the above. It will make your final product drinkable faster for sure. And your lees will be more compact. (or at least it drops out and clears faster)

Dadux
02-15-2017, 07:23 PM
Bit of extra imput: The longer you keep the lees on suspension by rousing the more clear the mead will get. Yeast cells attach in flocculation and their membranes bind compounds. I belive this is what Squatchy means by "eating up some chemicals" (as far as i know once they enter the sleep/dead fase they dont eat anything). So instead of racking soon rouse the lees for a month or two and it will get extra clear
Also some yeast strains say that if the wine (or in this case mead) is left on the lees, some flavours are added (positive flavours that is). Still got to figure this one out.
As to what happens after fermentation, that is floculation. the yeast cells either die or hibernate (they are not dead but are inactive.). they bound together forming clusters that precipitate forming the lees that for the sediment at the bottom. If you stir them up again, the clusters will have more and more cells. If not roused their membrane will break (this process is called autolysis) and release bad flavours into the mead. This is why you must rouse the lees if you dont rack, so this does not happen. This happens either when the sugar content is very low or when a number of factors make feeding and living difficult (such as high ABV, low pH, osmotic stress, lack of nutrients because of insufficient nutrition...)
So reasons to rack = clarify mead prior bottling/stabilization/backsweetening
Reasons to let it sit while rousing = Faster clarification, faster finished profile, faster sedimentation of certain proteins and compounds.

X-tian
02-15-2017, 10:30 PM
here's the conversation visually altered for the Q-A

i've looked around to find a yeasts life is in phases, and nutrients are time and/or sugar break scheduled. yeast phases are the lag, growth(accelerate,decelerate), ferment and stationary. nutrients are 24, 48, 72, and 168 hours or 1/3 sugar break (I'm thinking SP should govern these additions more than time but i'm still a nooby). So there are only 3 phases. Lag, Exponential growth phase and stationary phase. Most of all your flavor is made during the growth phase. The longer you keep your must in the growth phase the more esters you gain and the stronger your biomass will become. I keep my batch considerably cooler during this time than I will once we move into stationary.

I have two 3 gallon "traditional" batches nearing the end of ferementation, one now SP1.002 (OG1.08 and the other SP1.025 (OG1.102) WHat is SP? We call this FG * Final gravity

so ... what happens with the yeast beyond the "fermentation phase" (3-30days?) and even beyond the "stationary phase"? You should keep the yeast roused (stirred up in suspension) the entire time yeast are in your vessel. Until you finally want them to drop because you want to rack.

I guess I want to understand why to rack (or cold crash or add more chemistry) and not just let the batch sit and "age" for a few months? You do want to age with the yeast in suspension. The longer the better. They will eat up some of the left over chemicals they made during fermentation. This then will make your flavor profile cleaner. The longer they are in there will cause them to drop much faster once you decide to do this. The only time I would suggest racking off the lees as soon as your ferment is over is if you have had any sulpherish smells. If so then rack as soon as your ferment is over.

will the yeast die eventually or continue to ferment in ever decreasing %'s indefinitly (or until I personally filter them)? Over time they will die. They can only make alcohol as long as there is sugar to convert into ethanol. Or until their alcohol tolerance has been reached. Even if they stop assimilating ethanol because they hit their top end they still don't die right away. They just stop making ethanol. At least for a while. I have many times had a yeast tap out. If you add water or fruit juice into this state the water or fruit will lower the ABV and they will go back to work. I don't know for sure how long they can hang out at that ABV level before they die of Alcohol poisoning.

and how could that (letting it sit without racking) effect the quality of my product?
I already answered this in the above. It will make your final product drinkable faster for sure. And your lees will be more compact. (or at least it drops out and clears faster)


LOVE this conversation!! Good stuff for newbies!!

Trenchie
02-16-2017, 05:46 PM
Ok, I just found an article (main page) that touches on some of the questions I've had. he talks of racking and touches on a "new" yest phase (the secondary ferment): http://gotmead.com/blog/articles/the-mystery-of-the-secondary/

as for stirring (no maybe it should be called rousing) ... I guess that incorrectly stirring/rousing would introduce O2 and cause flavor issues. correctly would get you to maintain more yeast in suspension. I may have thought stirring to be something more subjective or opinionated but I'm thinking now, it depends on the yeast. really we are just harnessing yeast, like livestock and it's their success we need to ensure.

so now I i'm off to figure out what are the characteristics of my two yeast farms, er, mead batches. lalvin qa23 and pasteur blanc

-T

caduseus
02-16-2017, 07:51 PM
so now I i'm off to figure out what are the characteristics of my two yeast farms, er, mead batches. lalvin qa23 and pasteur blanc

-T

I dont use any red star yeast.
This may help you with QA23: http://www.eaton.com/EN/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestReleased&noSaveAs=0&Rendition=Primary&dDocName=PCT_868230

This is an informative PDF file on the yeast.

Here is more info: http://www.lallemandwine.com/north-america/products/catalogue/product-detail/9/wine-yeasts/27/lalvin-qa23/

Squatchy
02-16-2017, 09:14 PM
QA 23 is a very nice yeast. It runs slower than most other yeast. Cy3079 is also a slow goer. I persoanlly have not really cared for any of the Red STar line. But, I have drank a lot of good meads made with Pasture Blanc. I just like the smells they make on the way.

caduseus
02-16-2017, 10:13 PM
QA 23 is a very nice yeast. It runs slower than most other yeast. Cy3079 is also a slow goer. I persoanlly have not really cared for any of the Red STar line. But, I have drank a lot of good meads made with Pasture Blanc. I just like the smells they make on the way.

Ditto.
Squatchy when you did your experiment last year comparing different yeasts, did you do any bochets?

I am currently ageing a QA23 and CY3079 bochet dry to see which one i like more.

I am curious about your thoughts

Squatchy
02-16-2017, 11:36 PM
So I have made a few bochets. But the yeast test was only intended to compare yeast in a dry trad so we could clearly decipher the different nuances of each strain. Cy gives nutty, almond type notes pretty early on if you sur lie. It might go well in a bochet depending on what directions you are heading. My best bochets are ones with coffee and chai tea notes blended in together. Buckwheat honey (western) is nice. So is meadow foam.

I think too often people cook the honey too much. It becomes bitter and the bitter will stay around for ever. Same with nibbs. They get bitter if roasted too much. They also go nicely with a bochet. It's mostly false that cooked honey makes unfermentable honey. I find the most that it will have some residual is 5 %

WHat honey did you use in the CY and Qa?