Simple Yeast Storage Procedure

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Simple Yeast Storage Procedure

  1. Sanitize or sterilize jars. (Mason jars work nicely for this purpose. A quart size jar which will hold about 300 billion cells)
  2. Leave behind about an inch of beer when racking the beer off the yeast cake.
  3. Swirl the fermentor to suspend the yeast. (Avoid shaking as oxygen has a tendency to rouse dormant yeast)
  4. Pour the slurry into mason jars. (The typical 5 gallon batch produces three to four quart jars full of slurry.)
  5. Put the lids on just and snug them up. (The lid should not be tight. You'll want the yeast to be able to off gas while in storage.)
  6. Place the jars in the fridge (or freeze with 10% glycerin) until you are ready to use them.
Advantages of Simple Storage
  • Fewer processes steps and less contact with the yeast means there is a lower chance of contamination.
  • Alcohol, hops, and the PH of the beer provide antimicrobial properties.
Advantages of Yeast "Washing" or Rinsing
  • Alcohol is removed which can cause significant cell death above 8% ABV. [1]
  • Flavor components of the beer are removed. (The effect of the couple cups of beer in the next five gallon batch will often be trivial.)
Doesn't yeast washing separate the good yeast from the bad?
Unfortunately it does not. Water washing yeast is a common laboratory procedure for separating the dissolved compounds from the suspended material. It does not effectively separate out the suspended material. There will be some stratification, forming layers of partials that sink at different rates. Yeast that has formed flocks will sink slower than single cells. This, however, is independent of viability[2] [3]. In the end, separating yeast using water washing may result in a small amount of yeast that appears beautifully creamy , but the viability is the same as the large amount of yeast that was discarded. Another problem that is introduced with yeast rinsing is that the selected yeast are the slow flocculators. When this yeast is used it could result in cloudy, or slow to clear beer.

How long can you store yeast?

Yeast can be stored in the refrigerator for months. By adding 10% glycerin yeast can be stored in the freezer for years. A week of storage will have an impact on fermentation lag time[4] making it perform about as well as yeast from a vial that you would purchase from a home brew shop.

Do I need a starter?

In a blind taste test it has been shown that there is very little perceived difference in beer quality whether using a starter or pitching directly from refrigerated slurry.[5] In addition to increasing the biomass a starter will also activate the metabolism of the yeast. If the yeast has been in storage for more than a few days there will be a lag time while the yeast acclimates to fermentation. This typically takes less than a day. [4][9][10] There seems to be mostly anecdotal evidence indicating that off flavors are produced during this lag phase. [citation needed] To avoid this, a starter could be made from the stored slurry.

How much yeast is in these jars?

A safe estimate is normally 1.5 billion cells per ml of thick settled slurry. In the hundreds of cell counts I have done I have seen this range from 0.5 billion per ml up to 4 billion per ml.[6] It depends mostly on how the wort is prepared, but is also affected by the yeast strain.[7]


What is the viability?

Viability will depend mostly on storage temperature and storage time. The half life of refrigerated yeast is approximately 3 months. Frozen yeast will lose approximately 50% of the viability from the freeze,[8] but will drop very little in viability over time.[9] We can conclude from this that if the yeast is to be used within a few of months, it is best to store it in the refrigerator, and for longer storage freezing may be more appropriate.

[1] http://www.woodlandbrew.com/2013/01/abv-effects-on-yeast.html
[2] http://www.woodlandbrew.com/2012/12/yeast-washing-exposed.html
[3] http://www.woodlandbrew.com/2013/01/yeast-washing-revisited.html
[4] Murray, C. R., Barich T., Taylor D., "The Effect of Yeast Storage Conditions on Subsequent Fermentations", MBAA TECHNICAL QUARTERLY, Vol. 21, No. 4, 1984
[5] http://brulosophy.com/2015/03/02/sloppy-slurry-vs-clean-starter-exbeeriment-results/
[6] Woodland Brewing Research unpublished works
[7] Taylor, K., "YEAST HANDLING AND TECHNOLOGY", OCBC, 2014
[8] WELLMAN, A. M., STEWART, G. G., "Storage of Brewing Yeasts by Liquid Nitrogen Refrigeration", APPLIED MICROBIOLOGY, Vol. 26, No. 4, p. 577-583, Oct. 1973
[9] Woodland Brewing Research Viability storage research.
[10] N. B. PAMMENT AND R. J. HALL, Absence of External Causes of Lag in Saccharomyces cerevisiae, Journal of General Microbiology ( 1978), 105, 297-304.
***
Steven Deeds is the Woodland Brewer! For more from Steve be sure to visit him at his blog!

 
When I save yeast at all, I do the simple storage. US05, WLP051 and WLP001 usually. Those are the ones I use most often. For me, there's not much point in storing anything else as I won't use it again for many months.
Thanks for the info!
 
"Mason jars work nicely for this purpose. A quart size jar which will hold about 300 billion cells"
at 300 billion cells, for a normal gravity beer (say 1.050) wouldn't you end up over pitching if you create a starter? Or is the "over pitching" idea really not relevant on the home brew scale?
I am new to starters and yeast harvesting.
 
I mainly brew IPAs, so I have been reusing washed 1056 yeast for a few months now and while I see some lag in some batches, for the most part I am getting 80%+ attenuation in my beers. Other than saving money, I like the process of washing yeast, it is a fun part of the hobby.
 
@yukonhijack So what is "washing?" If I am going to use it for the same recipe of beer again cannot I simply pout and store??
 
@dokken5 That was the point. He is stating that you can just take the cake, suspend it by swirling, pot it, and then store it.
The point is to NOT "wash" the cake as you lose significant viable cells.
 
@dokken5 Depending on beer, you use a good estimate of 1.5 billion cells per ml of slurry.
So if you need 150 billion cells, use 100 ml of the slurry.
 
dokken5: The professional breweries don't buy new yeast for every batch either. Some breweries (with their own yeast lab) have been reusing the same yeast for 10 years.
If you want to pitch a precise amount, Mr Malty and BrewersFriend have a good calculators, although they give you vastly different advice. Or you can pitch a quart and call it good.
http://www.mrmalty.com/calc/calc.html
http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/
 
So for the average five gallon batch of Ale you need about 150 billion cells??
Thanks for the help guys. Up until now all I have done is dry pitch. Just starting to branch out a little.
 
So with the Mason jars, I read that the lid is not to be too tight. My question is, how tight is too tight? Aren't you worried about something getting in to contaminate? would a layer of plastic wrap under the lid be necessary?
 
Once the slurry has time to settle, it's going to separate out, isn't it? At that point, couldn't you just pour off the beer, replace it with water and recap? Or is that just unnecessary?
 
@The_Nid_Hog - The beer will help preserve the yeast until next use, as long as it's not a high gravity beer. The article estimates 8% before it's detrimental to do so. You're trying to keep as many viable cells as possible. I didn't wash until I was ready to build my starter, and even then I just gently swirled off the top layer of slow floccers, and dumped the rest of the slurry into my starter jar.
 
Another method to harvest yeast... do it from your starter.
http://brulosophy.com/methods/yeast-harvesting/
This is particularly helpful for high gravity beers as the article mentions that washing yeast from high ABV beers is preferred over "simple storage." If you harvest from the starter, you're doing this from a low OG starter wort.
Harvesting from the starter also results in yeast slurry that can be used across styles, as it's not affected by the presence of hops.
 
@dustinpettit - If you use the lid and ring, just set the lid on the jar and I turn the ring maybe half of a turn; just enough to keep it from coming off. I also use sanitized plastic wrap instead of the lid and tighten the ring a turn or so; again just enough to keep it on.
 
I use this same simple storage method. This year I have reused Wyeast 1028 at least 5 times now from beers with an OG of about 1050 - 1060.
Another great article.
Thanks!
TPH
 
Great article! I really enjoy reading your website. What a trove of useful information. Really appreciate the efforts you are making and sharing with the rest of us mortals. Stopped rinsing my yeast some time back after reading your blog. Thanks a mil.
 
Thanks for the article! I have been wanting to start yeast washing. However, this process seems more simple and effective. I will definitely give it a whirl on my next batch.
 
Thanks for the support everyone! Your feedback is highly valued.
Most of the questions that have come up in these comments seem to have been answered, which I appreciate. I'll try to answer the open questions, but if I missed yours, please feel free to ask again, or send me a PM.
@rhys333 Yooper actually asked me to write this article with the intent of making it a sticky in the Yeast forum.
@Singletrack Yeast from an all grain wort that is carefully transferred to minimize the amount of trub will be about 2 billion per ml.
 
Excellent article. I am (was) an long time yeast washer based on the original sticky. I've been following that thread and recently began using the method in this article. I brew weekly, and both methods have served me well. This is just easier.
 
I've not yet reused yeast, but would like to harvest the yeast from my current batch. I'd have a few pint mason jars. From what I read (100 ml at 1.5 billion cells/ml) would get me enough to pitch for a 5 gal batch, correct? That comes out to a little less than 1/4 pint.
 
I wonder if the author made a mistake when he said quarts? 4 quarts of slurry is a gallon. In the photo it appears the mason jar in the sink is pint size, not quart size. It is difficult to tell for sure though.
 
if you transfer to a secondary you can harvest the yeast then dry hop. I like my beers to fall clean so I always transfer to a secondary. Right now I have about a quart of yeast from the local brewery my friend owns. He took it from the port at the bottom of his 50 BBL conical. First he let the trub run out a little and what I got was a mason jar of creamy yeasty goodness. It has been in my fridge for about a month. I made a little wort from DME on the stove and cooled it down. Then I poured off the old wort that separated and added new. Like this article recommends I will make a started from this for the next batch
 
Sorry to resurrect an old thread, hope somebody finds this query.... :)
Great article, thanks for this, I am going to try and reuse the yeast from my current brew.
I have a question about repitching the stored yeast:
Do I swirl and remix the whole Mason jar and pitch the whole quart?
Or do I just pitch the beer layer?
Or do I chuck the beer layer and just pitch the trub layer?
Sorry for dumb question, I am new to yeast storage.
 
Magnis, in the few times I have used this method I just allowed it to warm up, swirled the whole jar and pitched it. It turned out good for me. You could also pour off some of the beer and pitch just the yeast. Hopefully there is not much trub in the mix.
 
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