Yeast Storage for next year

[JoP]

Just closed the bag and taped the top, then stored it into the post bag it arrived in. (This bag does not allow the light in).
Kept it in the fridge obviously.
Tested it a month before needed, so to give myself time to order another one.

Hi Obelix and all,

How do you test the yeast without using grape juice?

I tried some yeast from last year with sugar solution and it failed.

I did store the yeast in the fridge and was surprised that it did not show any life.

Please let me know about a solution that works.

Thanks

John

 

[salcoco]

get some G0-Ferm a yeast energizer. start with 20ml of water per gallon of finished wine for your must. heat water to 110degF add go-ferm at dosage of 1.25 grams per gallon of finished wine. let cool to 104 degF add yeast at dosage of 1 gram per gallon. wait 15 minutes wine yeast should be active.

 

[JoP]

get some G0-Ferm a yeast energizer. start with 20ml of water per gallon of finished wine for your must. heat water to 110degF add go-ferm at dosage of 1.25 grams per gallon of finished wine. let cool to 104 degF add yeast at dosage of 1 gram per gallon. wait 15 minutes wine yeast should be active.

Hi Salcoco,
Thank you for the reply.
I just want to test my yeast to see if it is still good.
I know how to use it, just looking for a proven method to test it without actual grape juice.
Sugar solution should work, in my case it doesn’t work, perhaps the yeast is dead.
Cheers
John

 

[Obelix]

I also used GoFerm, but I may have crushed a handful od grapes as I also couldn't activate it with sugar.
I say "may" , because it was 18 months ago, and don't remember clearly. Last year, I concluded it was dead and bought a new pack.

 

[salcoco]

I was hopeing the procedure I suggested would do it for you. you can reduce the amount of water to just 20ml and the other dosages accordingly. it will still proof the yeast

 

[JoP]

I was hopeing the procedure I suggested would do it for you. you can reduce the amount of water to just 20ml and the other dosages accordingly. it will still proof the yeast

Salcoco and Obelix,
Thank you for the feedback.
I tried with some crushed grape juice and it worked.
The sugar test did not show any signs of life, not sure why.
I forgot to mention that the yeast is Chr-Hansen-Viniflora-RHYTHM- that does not show a vigorous reaction when pitched like a Lallemand yeast, just some tiny bubbles on the surface.
It also has a pitching temperature of maximum 77F, versus the Lallemand yeast that needs to be around 104F.
Anyway, thank you for all the help.
Cheers,
John

 

[Fingaluna]

JoP,

There is a very quick method to check, it's staining the rehydrated yeast with Methylene Blue stain, giving it a short time to degrade the stain, and examining the yeast in a heamocytometer under a microscope. Blue cells are dead, and the cells that degrade the stain are living.

Sounds complex, but it isn't really. You do however need a microscope, a heamocytometer (a special kind of microscope slide with a grid and a 0.1mm gap between the cover slide and the slide itself) and the Methylene Blue stain. You can find the method online. There are ASBC, IBD, and EBC methods, I think, and they're all basically the same.

You can also use the heamocytometer to count the cells per mL to determine the pitch rate that you want in millions of active cells/mL.

If you get less than 80% viable yeast, it's a good indication that the yeast is stressed and will not likely do a good job in completing the fermentation, or may create off flavours due to stress.

You could also make a sugar/DAP solution at ~20 brix and look for CO2 generation.

Put 1/2 litre of solution into a wine bottle, add the appropriateaamount of yeast for the volume, aerate very well by shaking, then put a balloon over the mouth of the bottle and wait 12h to see if there is gas generated. If after 12h, the balloon has not significantly inflated (like, quite a lot), your yeast is likely no good. Not a scientific method per se, but CO2 generation is a good indicator of activity.

Remember that Dissolved Oxygen is crucial to yeast reproduction, so you need to shake well to entrain air/02.

You should use 125g/hL DAP to get to 250ppm of Nitrogen in your sugar/DAP solution.

Or lastly, you can just look at the situation to make a determination...:
If the yeast is in a sealed pack, and within stated shelf life it's likely good to be used.
If opened, the yeast will have lost ~5% of it's viability per week, due to it depleting its cellular Glycogen stores in the presence of O2/Respiring.
If it's open, stored warm, and past date, throw it out.
If it's closed, past date by a month or so, and stored cold, it's likely absolutely fine.

Good Luck.

 

[Obelix]

Glad to hear it worked John

Fingaluna, thanks for the education on other ways to test it.
What does DAP stand for?

 

[Fingaluna]

Obelix,

You are welcome.

DAP is Diamonium Phosphate, which provides Yeast Assimable Nitrogen / FAN (Free Amino Nitrogen.

FAN is required for cell membrane synthesis during yeast reproduction. FAN deficiency can significantly limit reproduction. Normal yeast pitching rates are typically "Seed Rates": enough yeast is added to out-compete other microorganisms, and to act as a Seed for yeast growth. You always want to have fresh daughter cells for the fermentation, as they do not have significant bud-scars on the cell wall / cell membrane (from budding/reproduction), so they have more active surface area for exchange of compounds in/out of the cell (sugars/alcohol), therefore fermenting more quickly. Additionally, the daughter cells ferment more vigorously, and more completely than mother cells.

General idea is to pitch roughly 1/10th the number of cells required for the ferment, then provide appropriate FAN and O2, allowing the yeast to reproduce to the ideal cell count. Some highly agressive Killer wine yeasts (and German Hefewiezen yeasts) may only need 1/20th seed rate. Ideal yeast amount can also vary by Brix, Temp, etc.

So, lots of aeration and appropriate FAN needed for healthy, off-flavour free fermentations.

Cheers

 

[Obelix]

Thanks for the explanation .
Is GoFerm actually DAP?

 

[Fingaluna]

GoFerm is a yeast-based product.
I believe that it may be similar to Yeast Hulls / Deactivated Yeast.
Will give you additional micronutrients than DAP.
DAP is good to add FAN if needed, while GoFerm is more for overall yeast health and rapid/complete fermentation.

 

[DizzyIzzy]

I'm certainly not the chemist/biologist, but I keep mine in the freezer from one year to the next and it seems to work fine. Glad you got to use most of it!

I freeze my bread yeast, so I wonder if wine yeast could also be frozen with ill-effect? That will have to be a question for the county extension agent?.........Dizzy

 

[JoP]

JoP,

There is a very quick method to check, it's staining the rehydrated yeast with Methylene Blue stain, giving it a short time to degrade the stain, and examining the yeast in a heamocytometer under a microscope. Blue cells are dead, and the cells that degrade the stain are living.

Sounds complex, but it isn't really. You do however need a microscope, a heamocytometer (a special kind of microscope slide with a grid and a 0.1mm gap between the cover slide and the slide itself) and the Methylene Blue stain. You can find the method online. There are ASBC, IBD, and EBC methods, I think, and they're all basically the same.

You can also use the heamocytometer to count the cells per mL to determine the pitch rate that you want in millions of active cells/mL.

If you get less than 80% viable yeast, it's a good indication that the yeast is stressed and will not likely do a good job in completing the fermentation, or may create off flavours due to stress.

You could also make a sugar/DAP solution at ~20 brix and look for CO2 generation.

Put 1/2 litre of solution into a wine bottle, add the appropriateaamount of yeast for the volume, aerate very well by shaking, then put a balloon over the mouth of the bottle and wait 12h to see if there is gas generated. If after 12h, the balloon has not significantly inflated (like, quite a lot), your yeast is likely no good. Not a scientific method per se, but CO2 generation is a good indicator of activity.

Remember that Dissolved Oxygen is crucial to yeast reproduction, so you need to shake well to entrain air/02.

You should use 125g/hL DAP to get to 250ppm of Nitrogen in your sugar/DAP solution.

Or lastly, you can just look at the situation to make a determination...:
If the yeast is in a sealed pack, and within stated shelf life it's likely good to be used.
If opened, the yeast will have lost ~5% of it's viability per week, due to it depleting its cellular Glycogen stores in the presence of O2/Respiring.
If it's open, stored warm, and past date, throw it out.
If it's closed, past date by a month or so, and stored cold, it's likely absolutely fine.

Good Luck.

Hello Fingaluna,
Thank you for the detailed explanation on a not so complicated, but not so readily available method for a small operation like mine.
You definitely know more about this than an average winemaker, I’m curious about your background in Enology, if you don’t mind sharing.
Cheers!
John

 

[CDrew]

As the original poster and questioning whether it was possible to hold the yeast over a year, I answered that question today. Short answer, is yes, it holds over just fine.

So what I did today was to make a GoFerm solution 40ml, and rehydrated 2gm Avante yeast per the usual directions for 20 minutes, and then added 25ml of 25 brix solution of sugar with a pinch of FermaidK. It took right off and there were CO2 bubbles within 15minutes. So in conclusion, the vacuum sealed, refrigerator hold over, works fine, and I'm going to use last years yeast (I still have 50gm or so) to start the first wine I do in 2020.

With the info provided by @Fingaluna, I can also recommend vacuum sealing your yeast, to prevent O2 driven respiration. You want it to stay dormant. The yeast manufacturers ship the yeast vacuum sealed, so it's likely important.

 

[user 36973]

I had an issue with some yeast I'd stored in the fridge for 1-2years stalling out halfway through the fermentation. Had to restart the fermentation with a EC1118 which was not desired. Real PIA.

I'm dumping all my yeast after a year after that. Not worth the few bucks saved if I have to pour good yeast after bad.

Update on this. I realized that the older yeast I thought was the cause of the stuck fermentation was more likely a result of insufficient yeast nutrients.

I had a similar issue this year with fresh yeast in a batch of juice from harvest the previous year. It is a more likely explanation for both of these stuck ferments that the nutrient levels were lower in the older juice. I'll be compensating with more DAP in the future for these type of batches.

 

[Fingaluna]

JoP,

You're very welcome.

My background...
I have been in the Beverage Alcohol industry since 1991, really mostly as a Technical Brewer / Brewmaster.
Diploma in Brewing Technology from the University of Sunderland (UK).
Diploma Brewer from the Institute of Brewing and Distilling.
Certificate in Malting from the Institute of Brewing and Distilling.
Volunteer Lecturer at a local College for their Brewing programme.
Have had the pleasure of making wine seasonally for a few years at one of the breweries I worked at.

Not really a specialist in oenology, but know enough to be dangerous.

Cheers

 

[Sailor323]

FWIW, I have checked the viability of yeast that has been stored in my freezer since 1997, its expiration date was 2003. It was still vigorous in 2020

 

[CDrew]

So I did the definitive test yesterday and initiated a 50 gallon ferment with my left over 50gm of Avante yeast. Primitivo grapes at 25 brix. Pitched just before bedtime last night and by this am was already forming a cap and ready for it's first feeding. I highly recommend the vacuum sealing if you plan to keep it over a winter.

 

[Ajmassa]

Just rehydrated some factory packaged d254 yeast from 2.5 years ago. Stored room temp Took off perfectly.

Did the same with 6mo. old avante in ziplock. Also not refrigerated. Also took off perfectly.

I like to live dangerously! Lol

 

[Ajmassa]

@mainshipfred I’m gonna give that fermentis hd135 a shot tonight on 30gal