Yeast Harvesting: A Novel Approach?

I began washing and harvesting my own yeast about a year ago. I got excited and harvested 4 jars from 4 batches in the first month, leaving me with 16 jars of 4 different yeasts. Since I usually brew twice per month, I had a ton of yeast just sitting in my fridge. After using some of this stored (aka old) yeast in beers that came out less than perfect, I began tossing it – hours of work, down the drain. Then I had an idea – why can’t I just harvest clean yeast directly from my starter? After trying out a few techniques, here’s the process that seems most efficient:

Step 1: Make a starter (3 days prior to brewing) that is .5 liter larger than you need for your beer. Since the majority of 5 gallon batches require no more than a 1 liter starter, a standard 2000 mL flask or even gallon growler will work great. In the photo below, I needed a 2 L starter for a 10 gallon batch, so I made 2.5 L.

Step 2: A couple days after making your starter, sanitize a 500 mL (1 pint) mason jar using the sanitizer of your choice. I prefer Iodophor.

Step 3: Fill the sanitized mason jar directly from the starter – if you use a stir plate everything will be in suspension, otherwise shake it up a bit prior to pouring.

As you can see, I poured about 500 mL of wort/slurry from my starter into the mason jar. After just a few minutes, you can already see the creamy white and very clean yeast settling to the bottom of the jar.

Step 4: Place the capped jar in the fridge over night to crash the yeast.

If you plan to use the yeast within a week or so, you can decant the “beer” and pitch directly from this jar. However, if you like to use different yeasts and won’t be returning to your freshly harvested yeast for awhile, you will want to store it in a more hospitable environment. Steps 5 and 6 address how to do this.

Step 5: Fill a 250 mL (1/2 pint) mason jar halfway with tap water then microwave it (without the lid!) for 2 minutes to sterilize and de-oxygenate the water.

Remove the very hot jar and put the lid on (using pot holders… it’s HOT!), then shake it up to sanitize the lid with the boiling water. Let this sit over night to chill to room temp. I usually do this right after harvesting my yeast from the starter.

Step 6: The next day, decant about 80% of the beer off of the pre-harvested yeast in the larger mason jar, making sure to agitate to release the yeast from the bottom of the jar. Then simply pour the yeast directly into the previously boiled water in the smaller mason jar.

Cap tightly and place in the fridge. Within a couple days you will have very clear water on top of a clean and compact yeast cake. When you want to use this yeast, make a starter as usual, decanting most of the water off the yeast, leaving just enough to help break up the cake.

Some of the benefits I see to this method include:

  1. The yeast is un-hopped and as clean as it’s ever going to be. In fact, this is basically how White Labs and Wyeast grow their yeast.
  2. Since you’re only making one jar of yeast, you won’t have to store a ton of yeast (some people won’t like this point).
  3. You don’t have to go through the “washing” process, which is a pain in the arse if you ask me.
  4. You can brew any beer you want, even a barley wine or RIS, and still harvest yeast, as you’re getting the yeast prior to it fermenting the beer you will ultimately brew. I guess you will need a pretty large flask, though.
I hope this helps. I’ve used the same strain multiple times very successfully. I’ll never go back to washing yeast again.



169 Responses to “Yeast Harvesting: A Novel Approach?”

  1. eimar on

    Thank you Brulosopher for taking some of your valuable time to post that interesting tutorial.
    I might have missed the most important point: For how long can you store that yeast cake ( under water ) in the fridge : weeks?, months? years ?
    Best regards


  2. bierzwinski on

    That is a good idea, and similar to mine. I have started to make 5 starters from one vial if Whitelabs. Personally, I think it works great. All my beers have taken off really well with this method. I brew two 12 gal batches at a time, therefore 4 carboys. Using this method, I have one left over to make more starters with.

  3. BigB on

    Everything makes sense, except I don’t get the point of transferring to the smaller jar. Why not just leave it in the first jar and decant the beer off the top, then pitch the yeast directly into a starter?

  4. nickmv on

    Not following the logic here. You say that you see the yeast settle to the bottom, but everything I’ve read says that TRUB is the primary sediment that settles to the bottom initially.

    All other guides call for decanting the liquid above the trub into another jar, this liquid being full of yeast. Then, after chilling, the yeast settles out. Am I missing something? Yeast should take a decent amount of time to come out of solution at room temperature.

  5. Brulosopher on

    @BigB You can absolutely do that, I just prefer to leave my yeast under a bed of deoxygenated and sterile water if I don’t plan on using it for a couple weeks. It’s just a safety precaution… and it only takes a few minutes.

  6. Brulosopher on

    @nickmv A couple things… first, when you’re washing used yeast, trub will most certainly settle to the bottom first, and rather quickly, hence the reason you’d let it settle for a few minutes then decant the beer off the top and proceed. However, with this method you are harvesting yeast from a purely malt (unhopped) starter that has a stir bar keeping everything in suspension. Given the fact the volume is so small, it’s unlikely there is too much protein or lipids like you get in a 5+ gallon fermentation.

    Second, the yeast I used in the demo was WLP002 English Ale, which is known for flocculating and dropping out quickly. This is mainly why you see the layer at the bottom. When I’ve done this with less flocculant strains (e.g., WLP001), it takes a few hours for the cake to form.


  7. BDun on

    I think your metric to English volume calculations are off.
    500 ml is roughly a pint (not 1/2 pint). Also, 250 ml is roughly 1/2 pint (not 1/4 pint).

    Other than that this looks interesting. I used to wash yeast post-fermentation but stopped when I went to 10 gallon batches using a stainless keg. I may now start harvesting from my starters.

    I just tossed a few washed samples that were 2 to 3 years old. They still looked and smelled o.k. but I didn’t test for viability.

  8. Brulosopher on

    @nickmv A couple things… first, when you’re washing used yeast, trub will most certainly settle to the bottom first, and rather quickly, hence the reason you’d let it settle for a few minutes then decant the beer off the top and proceed. However, with this method you are harvesting yeast from a purely malt (unhopped) starter that has a stir bar keeping everything in suspension. Given the fact the volume is so small, it’s unlikely there is too much protein or lipids like you get in a 5+ gallon fermentation.

    Second, the yeast I used in the demo was WLP002 English Ale, which is known for flocculating and dropping out quickly. This is mainly why you see the layer at the bottom. When I’ve done this with less flocculant strains (e.g., WLP001), it takes a few hours for the cake to form.


  9. Brulosopher on

    @RmikeVT Right on, man. I’ve been using this method for the past few months and it has been working fantastically. I’ve got a couple strains that are on their 4th and 5th generations, and they still get going like crazy, making great beer. Good luck! If you have any questions, don’t hesitate to ask.

  10. Brewitt on

    I’ve been doing the same thing with either yeast recovered from bottles of bottle conditioned beer or from a vial of White Labs yeast. But I take it one step further. I freeze the yeast for long term preservation. I just wrote an article on the process of freezing the yeast that was posted in the article section that is based on the approaches discussed in the thread on freezing yeast. Take a look.

  11. jammin on

    Bravo. All I can say is, “why didn’t I think of this?”

    Seriously though, thank you very much! Can’t wait to get going on it.

  12. goodheadale on

    Thanks so much for sharing! I like the idea of using “clean” yeast as well as time saved.
    I will be using this process!

  13. flips on

    Wow! This is so simple and makes so much more sense than washing! Genius!

    I just tried to do my first wash this weekend. After watching a lot of videos and looking at a lot of photos I couldn’t tell if I was pouring trub or yeast. My thin white line was really, really thin, so after all that messing around I’m not sure anything is even viable. This solution seems so much easier and so much cleaner! I will definitely do this on my next starter! Thanks for sharing!


  14. bristela on

    Is there a benefit to doing this rather than making a “glycerol” stock and putting it in the freezer?

    I’ve tried using malt extract instead of glycerol as a cryo-protectant and it seemed to work just fine. Had to grow up the starter culture days in advance though as I’d only made small aliquots.

  15. codeJockey on

    Brilliant. This is one of those “Why didn’t I think of that?” ideas. I will have to try this following my next batch, in which I am using yeast harvested the old-fashioned way 😉

  16. Huaco on

    YES! I am about to make a starter for a brewday coming up. I think I may just have to pull some of this off and start saving my own “parent yeast” I live over an hour away from my LHBS and it would be nice to build a “library” of sorts in my beer fridge of commonly used strains.

    Thanks for taking the time to do the write-up man! Appreciate it!

  17. LeroyWhite on

    I’m confused by step 6

    “decant about 80% of the beer off of the pre-harvested yeast in the larger mason jar, making sure to agitate to release the yeast from the bottom of the jar. Then simply pour the yeast directly into the previously boiled water in the smaller mason jar.”

    Is the 80% discarded and the remaining 20% poured into the boiled water? If so, why would you agitate the yeast during decant? Wouldn’t this mean that you’re discarding a large percentage of the yeast?

  18. senordodo on

    Genius! I never thought washing the yeast after a full fermentation was a good idea, inbreeding over too many generations and all.

  19. Brulosopher on

    @LeroyWhite Before agitating, pour off (decant) about 80% of the basically clear beer sitting on top of the yeast, then agitated the jar just to remove the yeast from the bottom… it’s sticky stuff 😉

  20. shoshin on

    Awesome!!! I have about 12 1/2pint jars in the back of the fridge holding multiple jars of washed yeast from 3 strains. SWMBO was a bit iffy at me taking up so much room in the fridge, but taking this approach will definitely cut down on the necessary fridge space to keep my growing library :) Thanks, Brulosopher!!!

  21. Bisco_Ben on

    I did this for the first time today and before I got the yeast going I went to the local hardware store and bought a pack of the pint mason jars. Now I have a bunch of these and was wondering if it is really necessary to now go buy 1/2 pint mason jars as well. I would really rather be able to use another pint jar for the 6th step if possible to save on costs.

  22. royale on

    Great post, thanks! One question I have is how can we determine how many billion cells are in that 500ml slurry? We know one vial or smack pack normally range from 100 to 130 billions.

  23. Brulosopher on

    @Bisco_Ben Nah, it’s not really necessary. In fact, I just harvested from 2 smaller jars then combined them a couple day later with the boiled water. Worked great!

    @Royale I really have no clue how you’d get an accurate cell count without using some sort of really nerdy lab equipment… which I kinda wish I had… but alas…

  24. ultravista on

    Brulosopher – good stuff. I have saved some starter yeast before and also washed (well sort of) before too. I like your process and will start doing this for the next batch.

  25. Brewsday on

    How about this??? Make the big “1st generation” starter (say 1.5 liter), pitch half to new wort, refill starter flask with saved new wort made that day, 2 days later harvest about 4 jars of “2nd gen”…over time, use 3 and when get to 4th, do this again and harverst 4 jars of “3rd gen”.
    I’ve been harvesting/washing yeast for a while but worry a little about generations as I’ve read things can start to stray in 4 or 5 gens. (that said I’ve yet to detect any issues)

  26. Brulosopher on

    @onthedot Yep, easy-peezy

    @Brewsday Sounds good to me, do it and report back. I don’t like having all the yeast lying around, so 1 jar is good enough for me.

  27. Brulosopher on

    @MaltyHops – Very, very good point. In fact, I’ve experience the superheat phenomenon and it’s scary. For those concerned about it, I think your recommendation is a good one. For me, I’m comfortable with my current process. Another option is to put a wooden stir stick in the water when you put it in the microwave. Thanks!

  28. onthedot on

    Well I am here to report that I tried this method and so far it is a success!

    I am making my first starter with harvested-yeast. I am making this one 500ml larger so I can continue to harvest yeast perpetually :)

    Is there a point when yeast has been over-harvested?

  29. sorefingers23 on

    how long can i store the yeast in mason jars (without doing steps 5 and 6)before reusing them? and would i have to make a small starter before pitching?

  30. Brulosopher on

    @sorefingers23 I would think 2-4 weeks would be fine; the deoxygenated water is simply a better medium for dormant yeast. I would definitely recommend making a starter before pitching- I always do. I just made a starter yesterday using yeast I harvested 2 months ago and it took off within 8 hours.

  31. onthedot on

    I have the say that I love this method! I looked into a few different methods of recycling yeast and this is by far the easiest and most convenient so far!

    One question: Is there a picture of the ‘proper’ amount of yeast in the final jar? I am not sure if I am cultivating the amount that I should, I think a visual comparison would really help both me and others.

  32. Brulosopher on

    @onthedot I should take a couple pics and post them, but to answer quickly: I usually get about 1/2″ of yeast at the bottom of the jar after a few days of settling.

    Also, for those wondering about yeast viability, I found this on the White Labs website:

    “Generally, when reusing yeast from a fermentation, half of the yeast dies in the first month. So by 2 months you only have 10-30% living cells. For White Labs Yeast, the yeast is lab grown with a special media and process, extending the shelf life. If you want to store yeast after fermentation, we would recommend a maximum of two weeks and releasing the pressure in your container every other day. Some people do go longer than that, but the results are mixed. It is also difficult without a lab to check the quality of the yeast before reusing.”

    Of course they would prefer if we never harvested our yeast! Oh well. I just made 2 starters, one from 3rd gen WLP002 and the other from a 4th gen WLP090- both took off quickly while on the stir plate and began vigorously fermenting 2 seperate IPAs within 8 hours. So…

  33. UofMontanaAlum on

    I wanted to thank the OP for sharing this idea. It has taken the cost of buying a $6 smack pack out of almost all of my beers. I haven’t purchased 1056 in months!!

    I do it slightly different. Rather than pitching half the original starter into a fermenter, I toss the entire 2000ml flask in the fridge for a day. I then decant the spent beer off the top of that and split the remaining yeast cake up between 5 pint jars of boiled water. (I use the method from this thread to boil/sanitize my jars/water … ) A couple days before brew day, I pull a jar out and build a starter for that beer. When I get down to the last jar, I build another 2000ml starter and repeat the process of splitting it 5 ways.

  34. WileECoyote on

    Well done Brulosopher, Great Idea and Great write-up, clean un-hopped yeast is exactly what Im looking for, as I also make all herb brews.

    What do you use to make your starters with DME? or? and quantities?


  35. Brulosopher on

    @WileECoyote Thanks, man! I use a ratio of 10 grams DME to 100 mL water; so for a 2.5 L starter that’s 250 grams DME.

  36. thetmaxx on

    Thank you, I was reading this while learning about yeast washing, etc.

    But I would also like to point our the danger of superheating water in the microwave, it can happen, look it up on youtube.

  37. gamb0056 on

    Great article. One thing though, if you cap your boiled water and then shake it to sterilize the jar lid, you’re most certainly reintroducing oxygen into the water.

  38. Brulosopher on

    @thetmaxx: This is absolutely true, so be careful! 😉

    @gamb0056: Good point. I actually don’t shake, but gently roll the jar so that the water touches all parts.

  39. doublehaul on

    Is the 500ML jar you end up with the equivalent of a wyeast pack or white labs vial? So you would just make a starter with this for one batch, and make 500ML extra to repeat the process?

  40. onthedot on

    I use Mr. malty to calculate my starters.

    What is the yeast viability date for this method? Do you use the date stamped on the original package of yeast from wyeast/white labs? Or do you use the the date you most recently harvested from a starter?

  41. mkravitz13 on

    chiming in with others here on this magical post:
    onthedot said:
    “One question: Is there a picture of the ‘proper’ amount of yeast in the
    final jar? I am not sure if I am cultivating the amount that I should, I think a visual comparison would really help both me and others.”

    my question is in the post below:

  42. mkravitz13 on

    so, for your mini yeast samples (the ones in sterile H2O), how do you figure how much yeast from your sample to add to your starter to meet your appropriate pitching rate for your batch of beer?

  43. Brulosopher on

    @mkravitz13 That’s a good question. Unfortunately, I don’t think too terribly hard about this piece of it, particularly since the amount of yeast that ends up in the jar (I’ll try to add a pic) looks to be a tad more than what comes in a vial. I make an ass out of u and me that there’s roughly the same amount of healthy cells in my jars as there are in a vial. I’ve used numerous strains multiple times using this method and making a starter (I prefer using the date I collected the sample as the “manufactured date.” If/when someone decides to do a cell count, my ears will be open. Either way, my beers have come out absolutely fantastic using this method, better in fact than when I’ve started with a vial… this from some of my friends on tried and true recipes. So…


  44. Brulosopher on

    @d_striker I’m nowhere near smart enough to accurately answer this question. Umm, my best guess is “enough.” 😉

  45. lstrowge on

    I’ll add my thanks for posting the original method as well. I’ve been “attempting” the yeast washing from feremented batches for about a year now and have had mixed resluts. Your’s definitely looks to be a better method than I have been doing. One thing that may help with the issue of superheating jars, I have been boiling a quart jar and 4 to 6 jelly jars in water and then capping them full. I recently have had left over jelly jars that I set aside and use that now sterile water to mix for my second washing. I intend to pre-boil/package sterile water/jars for use with your method. Avoiding the microwave altogether. I just have to dip the jar in star san (closed ofcourse) before i uncap and pour.

  46. Brulosopher on

    @lstrowge That’s a great way to sterilize both water and jar, in fact I’ve done it before as well. I simply like the the ease of using the microwave. Cheers!

  47. Weezy on

    First off, this is *awesome*…thank you! I think I might go about it like UofMontanaAlum suggested about just splitting the first starter up into several jars for refrigeration, rather than pitching any of that original starter. Make new starters from those jars for use. Let’s call it an initial harvest.

    I’d like to recommend a slight clarification to Step 6 (recommended additions in CAPS):

    “Step 6: The next day, decant about 80% of the beer off of the pre-harvested yeast in the larger mason jar, WITHOUT DISTURBING THE YEAST ON THE BOTTOM. LEAVE 20% OF THE BEER TO HELP agitate AND release the yeast from the bottom of the jar. Then simply pour the yeast directly into the previously boiled water in the smaller mason jar.”

  48. fall-line on

    Good post, this is pretty much exactly like what I’ve been doing since having similarly suspect results with washing. Since my stir plate and flask are capable of growing very large colonies of yeast (much larger than a 5 gallon batch requires), it’s easy to just make a little extra for later.

    I haven’t been transferring to the smaller jar with boiled/cooled water though, I’ll give that a try.

  49. Accidic on

    Maybe I’m just being really dense here but I’m not really clear on why this is so much easier than “Washing” (read: rinsing) the yeast to begin with. For all intents and purposes it’s still seems like the same process, just nailing it from the starter (and likely hopless) rather than the Primary. I’m not knocking it, I’ve done the same process previously and just used it as a base for a starter when I had two batches that were going to be down near simultaneously but brewed at different times.

  50. Brulosopher on

    @ fall-line: The sterilized/de-O2 water part is done only to provide a more hospitable environment for longer term storage. If you use the harvested yeast within 2-4 weeks, I’m not even sure that part is necessary.

    @ Accidic: Not dense at all! It’s not really the same process because there is not yeast washing (really “rinsing”) part to this method. You simply pour .5 liter of wort off of a starter and save it for later. This takes me a whopping 3 minutes. Harvesting and rinsing (multiple times) yeast that has already been used in a beer usually took me at least an hour, as I had to wait for the yeast to stratify, blah, blah. Plus I always ended up with 4 jars, which I’d usually end up tossing 3 of. And yes, I absolutely prefer the fact the yeast I collect using the starter method is hop free, the only junk I collect is a little protein break material from the DME, which is no biggie. Hopefully that clears some things up. Cheers!

  51. Jbear on

    Brulosopher – good write up! I’ve been utilizing pretty this exact practice for the last year or so with outstanding results as well. I don’t usually store longer than a couple months, so I actually don’t decant my saved culture from under the starter beer and have not had any problems.

    Regarding estimating your cell count in the saved slurry that some people have asked about. Here is how I do it: Using the OP’s example of 2.5L starter with .5L saved, 20% is kept. So if mrmalty/yeastcalc says my 2.5L has, for example, 220 billion cells, I estimate that I have kept 44 billion and use that + the date for the next batch. Given that is ~1/2 of a smack pack, stepped starters really become your friend.

    @Accidic – it seems a lot easier than washing/rinsing to me because there’s very little trub to get rid of in 500mL of starter wort, so I don’t bother with it. Also, when making a starter I’m already in the kitchen with the stove on so getting a jar ready is easy while waiting around for my starter to boil. With washing I found myself either waiting to rack beers, or racking and just tossing the yeast anyhow because I didn’t have various sizes of jars sterilized.

  52. Brulosopher on

    @ Jbear – I was thinking similarly regarding the cell count thing, I just didn’t want to make the erroneous assumption my thinking was right ;). It makes a lot of sense to me, theoretically; however, what doesn’t make sense is that I end up with more yeast slurry in my jar than I’ve ever seen in a WL vial, which seems to contradict the idea there are only 40 million good cells in there. Also, I’ve never stepped up a starter using this method, even on 1.065+ beers, and they all get going within 12 hours and turn out fantastic. I’m admittedly confused… in a good way!

  53. ViperMan on

    Question – when you make a starter with an extra .5 liter, do you add 25% more DME?

    I’m going to try this out ’cause I’m tired of buying yeast vials all the time…

  54. Jbear on

    I don’t have a microscope, so all I really have to base my assumptions is doing the math. I do agree with you that my saved batches appear to be at least the size of a vial, if not more. I have always figured it is mainly trub, since we aren’t washing/rinsing the sample. Its pretty clean trub, however, being an unhopped all DME wort only boiled for ~5 minutes so I think it blends with the yeast better. This explanation is my personal experience, but unless all the yeast calculators out there are off by 100s of billions – I just don’t see how we can have more cells than that.

    In practice, I have not done many stepped starters either, because I rarely start it far enough ahead of brew day for the extra chill/decant days. However, I’m brewing more 10 gallon batches these days I am starting to force myself to plan better. As an example starting with 97b cells (the default) you can hit 507b cells with a 5L starter. Or you can hit 506b with 2 1.4L starters. (all are stir plate numbers) Over time that 220grams of DME saved will add up!

  55. Brulosopher on

    @ViperMan – Not necessarily 25%, as the amount of DME I use ultimately depends on the volume of my starter. Let’s say a certain recipe calls for a 2 liter starter, usually I would use 200 grams DME. But if I plan to harvest some yeast from this starter, I’d make it 2.5 liters and add 50 grams more DME. That said, there’s been some very good conversation regarding the actual number of cells we’re harvesting using this method… see Jbear’s comment below :)

    @ Jbear – You make some good points, man. I’m really excited for someone who has the knowledge, skills, equipment, and interest to step up to the plate and count the harvested cells. It’s so weird that multiple small volumes of wort will result in more cells than a single flask with even more volume than the multiple combined. Huh.

  56. Jbear on

    I stumbled across a fascinating thread that is discussing the very topic of yeast growth in starters. Several people there confirmed what I understood, which is that there is an ideal pitching rate specifically for yeast propagation (which is different then the ideal fermentation pitch rate).

    The thread then goes on to question whether sites like Mr Malty or Yeast Calc are accurate, specifically for stirred starters – which both you and I make. Of the science oriented folks, the consensus seems to be they are fairly accurate for still/aerated starters, but some are seeing much larger growth than calculated with a stir plate. And that could certainly explain what you and I see in practice – which is that jar sure looks like more than 40b cells!

    Here’s the link:

  57. Brulosopher on

    @Jbear – Thank you so much for that link, I’m looking forward to perusing it. I’m glad I’m not the only one who seems to think I’m pulling way more than 40-50b cells.

  58. scifi_13 on

    i think the next starter i make may have this in mind. since i usually go back and forth on 3 or 4 ale yeasts.

  59. RatsoRizzo on

    Thanks Bru, been trying to decide the best way to get more than a few brews out of a yeast as I brew small batches and yeast is too expensive at one vial a batch. Think this looks like the best option.

    Quick question: when you first pour off 500 ml from the starter and place in the fridge do you have to worry about carb build up in the sealed jar or does the fridge temp stop any fermentation straight away. Don’t want any jar bombs in the fridge.

  60. Brulosopher on

    @RatsoRizzo – Personally, I’ve never “worried” about that issue or experienced any problems with it, as I only collect yeast after it is at least almost close to fermented out. Also, mason jars can take some pressure. That said, is it possible to create bombs? Probably, but if your process is good and you’re using good jars, I have a hard time seeing how it would happen. Cheers!

  61. Bamsdealer on

    The metal on the lid will fail long before the jar does. I know from experience. As far as I can tell, it’s not from additional fermentation, mainly CO2 buildup. Just off gas as best you can before you can your yeast. Only one lid bulged in the fridge, the other two failed when I took the yeast slurry out to warm up. Both times I got a faceful of yeast.

    Bru, I’m using this method from some 1450. Just now coldcrashing a pint of the starter. The other quart went into a porter I just brewed after work.

  62. oldbullgoose on

    Here’s a question: I know breweries will use yeast 6-10 times with the best fermentations happening on the third or fourth round of reusing the yeast. What process is going on that improves fermentation and do you get the same effect using this process (which I love…) or might this be an advantage to washing yeast the old fashioned way?

  63. Brulosopher on

    @oldbullgoose – Hmm, I haven’t a clue, really… but the second and third gens have produced fantastic beer!!

  64. oldbullgoose on

    Here’s a question: I know breweries will use yeast 6-10 times with the best fermentations happening on the third or fourth round of reusing the yeast. What process is going on that improves fermentation and do you get the same effect using this process (which I love…) or might this be an advantage to washing yeast the old fashioned way?

  65. barleyfreak on

    Great idea. I’m going to try it with my next vial tomorrow. Is there any particular reason the final decant is into a 1/2 pint jar? Would there be a drawback to using pint jars for the final with air space? I possess way more pint than 1/2 pint.

  66. Brulosopher on

    @barleyfreak – I don’t think it’d matter a single bit, I wrote this up for the person (ahem, myself) who would be purchasing new jars. Actually, if you have the ability and you plan to use the yeast rather quickly, it’d probably be good if you collected a full pint of the starter, which you could then pitch directly into your next batch. Cheers!

  67. humpadilo on

    I am pretty new to brewing, 3 months. I think this is really great article and idea. I am deffinately going to start trying this. My wife is just about done with her Medical Lab Tech school and she said she can probably give me a good count of the yeast cells. I think I will try this next week and hopefully post a good count.

  68. taekwondd on

    I’ve made a few starters using yeast I’ve harvested and every single one has been really aggressive. I used to be able to make a 2L starter in my 2L flask but all of the starters I’ve made with the harvested yeast have blown my foil lid off and made a nice little mess on the counter. I’m assuming it’s just because the yeast is much younger than it would be from the vial? I think it’s time to buy that 5L flask I’ve been eyeballing.

  69. mrkrausen on

    I love this idea. I’ve already got a mini fridge filling up with washed yeast as we speak. I wish I would have known about this sooner. And I agree with Taekwondd, I’m gonna need a bigger flask!

  70. Brulosopher on

    @taekwondd – Haha. Yeah, I find myself using my 5L flask for lager/hybrid yeasts or for older yeasts. It works quite well. If 2L is the right size, pick up some FermcapS for about $2 and add a drop or 2 to your starter, it’ll kill that blowoff right good!

    @mrkrausen – You go, boy, get that bigger flask 😉

  71. simie on

    Awesome thread…Will definately be exploring this process. What a great idea. Will report back on progress.Thanks Bru! and others.

  72. DanPoch on

    I’ve been contemplating this lately. I was thinking about making a starter as soon as I get my yeast and then put part into a few jars to save for the next batch.
    Thanks for the write up, this is a big help. I can do this right when I get the yeast and have a few jars to use for my next few beers.

  73. Brulosopher on

    @DanPoch – Right on, dude. While we’re still unaware of exact cell counts, I tend to think pulling off a full pint will get your right around 100 billion cells (the same amount in the commercial packages); when my 1 pint mason jar is in use, I’ll simply fill two 1/2 pint jars then combine them later. Or, you could easily get away with building up a starter from the 1/2 pint pull, but I would recommend setting your “initial cell count” in whatever calculator you use to 50 billion cells, just to be safe. Cheers!

  74. arborman on

    This is awesome, and I want to do this…

    My question is this: How do you really know how many cells you have when you pour it off into your mason jar? Based on .5 liter, should we assume this equates to one vial of yeast if bought? And, when you make a starter with this new yeast, what date are you entering in for production to calculate vitality when making a new starter? The date that you harvested?

    Thanks for posting this!

  75. Brulosopher on

    @arborman – Answers, in the order you asked:

    1. We don’t really know, we can just estimate. Using Kai’s stirplate setting at, we can estimate there’s approximately 100 billion cells. Anecdotal evidence suggests however many cells are there works beautifully 😉

    2. ! vial/smackpack has 100 billion cells… we estimate there’s approximately 100 billion cells in our “pull” off the starter. Make of that what you will.

    3. I enter the date I harvested the yeast from the starter, yes.

    Hope that helps. Cheers!!

  76. arborman on

    Great, thanks for the feedback.. So, lets say I have a vial of yeast that I want to bank…. If I do a 2500 liter starter with it, I can then break that down into 5 mason jars, and roughly go by each jar as if it was a vial of yeast? If so, sounds like an easy way to build up a bank of yeast at home… Seems like more people would just do a starter for a batch, then add a bit extra to harvest… anything wrong with just doing a starter with the purpose of harvesting all of it for future batches?

  77. Brulosopher on

    @stvo – Glad you appreciate it! I currently keep between 4-6 strains of yeast on hands at all times, which allows for a great variety of beer. I also really enjoy sharing pulls with buddies.

  78. sudsstud on

    The advantage to pitching the proper amount of cells to an appropriately oxygenated wort, and letting it ferment to completion is to allow the yeast to complete the cycle and build up it’s cell walls and and reserves and go dormant as healthy as possible and be ready for the next batch.

    One vial or smack pack is enough for 5 gallons of 1.040 wort. If you pitch that into 5 liters, won’t the larger amount of cells use up the resources before they can complete their cycle and go dormant in a healthy manner? Won’t crashing before the yeast can complete it’s cycle compound this issue? I believe you may be simply growing a bunch of very stressed yeast cells. A starter will grow more cells from a new pack or vial or slurry but should be pitched while active.

  79. Brulosopher on

    @sudsstud – I’m not sure where you get your info, and I’m certainly no microbiologist, but some of the best homebrewers out there crash their starters before pitching. Also, I know it’s anecdotal, and I certainly know what a beer made with stressed yeast tastes/smells like, but my beers are coming out very well. Cheers!

  80. GuldTuborg on

    This sounds so much easier than harvesting from a carboy after racking/bottling. It’s obvious, in retrospect, though I never would have thought of this myself. Thanks for sharing…I know how I’m going to be harvesting my yeast from now on.

  81. sudsstud on

    @Brulosopher – sorry I must eat my words. After 19 years of brewing, sometimes I think I know everything. After some research, I concluded that your method is legit.
    I’ll stick to rinsing my yeast post-fermentation just the same but that’s a nice article and technique. Kudos!

  82. santero on

    thanks for the info brulo ! my question is ? I usually do a 36 gallons batches and I use 2 flask of 5000 ml I usually do a 3 lts starter with 3 vials per flask , if I using only one flask do I have to do a 4.5 lts starter and then fill 3 jars and the remainder do it as I usually do ? or what will the best approach in this case ?

    thank you !

  83. imrook on

    Nice post. I actually started doing this a little while back too. I bough a few expired tubes of White Labs yeast dirt cheap. I started with a very small starter and began stepping up. During the process, I realized that I had nursed the yeast back to health and I could harvest directly from the starter and have a pretty good quality sample to bank for the future. I like the fact that it is an easier and cleaner harvest process and I store much less volume of yeast in my beer fridge.

  84. diodeart on

    I really like this method, i’ve been doing it for a few months. I then pour the yeast back into a white labs vial and it gives me a ballpark on my yeast numbers as related to the amount i buy.

  85. Chazmatic on

    Have you ever let your starter wort settle & stratify, then decant off its trub before pitching yeast to collect the purest samples? That said or asked as the case may be, I’ve read articles that suggest there is some nutrient value in the trub that benefits health yeast growth. Have you come across any information like this in your research?

  86. Brulosopher on

    @Chazmatic – I haven’t… and I don’t plan to. I’d be afraid I’d harvest only the least flocculant cells. Plus, this method has been working great.

    @jeffd10 – Stop buttering me up.

  87. MachineShopBrewing on

    For those who are wondering how many cells are in the slurry that you save. I have always used the mrmalty repitching from slurry tab to estimate the number of cells in my slurrys. If you have a graduated vessel you can measure the number of mls of slurry and use the mrmalty slider to estimate the number of cells based on volume. The default setting will take account for a normal level of trub.

    I bought a bunch of 100ml- 1000ml flasks that I use for harvesting and measuring yeast. You can just pour it into a 500ml or 1000ml flask instead of the jar and cap it with saran wrap. Then, once it settles, you can keep in the 500ml or transfer to a 250ml flask with sterile water. The 250ml flask will make it easier to measure.

    To use the mrmalty site to estimate yeast solids, just plug in a random beer number until it shows you the same number under “# ml of yeast needed” that you have in slurry. Then the ” # of yeast cells needed (in billions)” number should be close to what you have as long as you leave the sliders in the default settings. Then you can plug that number into the site and figure out how you want to go about growing up enough for the next pitch.

  88. CraigerBrau on

    I tried washing a couple times with the most recent being WLP002 out of an ordinary bitter. For all the reasons you listed, I decided it’s not worth the effort.

    Your method makes perfect sense and I can’t wait to try it with my next starter. Thanks!

  89. jbsayers on

    I started brewing last September. When I made my first starter for my 2nd batch I thought of this, posted it on the forums asking if anybody else did it or if there was a reason not too and most of the replies were along the lines of, “why would you do that!?” Felt like a newbie doofus for asking…did it anyway, lol. Happy to find out it wasn’t such a bad idea! Thanks for the vilification!


  90. Brulosopher on

    @jbsayers – I’m glad you like the method! I just took a look at the thread you mentioned and noticed a friend of my (krispy3d) actually recommended you take a look at the original thread I started regarding harvesting from starters, which I posted a month prior to you. We must have been on a similar wavelength or something. Cheers!

  91. nitton on

    I like this method, and have used something similar in the past. I do offer one suggestion: it may be a better plan to store in isotonic solution rather than tap water. The logic behind this is explained here (not my blog):

    It’s very easy to make at home using table salt and distilled water. If storing in tap water that is only boiled is working for you, this should work just as well if you don’t have a pressure cooker (neither the microwave nor boiling can actually sterilize the water). With the amounts involved and the fact that you’d be decanting the storage medium there is no problem that the liquid is salty.

    I’ve been using this for my yeast ranching and have not had any issues. I store a tiny amount in 10mL vials and use several step-ups to get enough yeast. However, I do use a pressure canner and sterile, disposable plastic instruments that anyone can buy online.

  92. coldandbitter on

    I’m using this method right now. Just jumped up my Sierra Nevada stock to use in an upcoming APA batch. Thanks for the idea!

  93. Newgene on

    This certainly beats the steps in yeast washing from a previous batch. I do this all the time with dry yeast to give me a ton for future use. The beer always comes out great because I never worrying about having enough yeast to pitch. Combine this with the process of stepping up yeast, and you never have to worry about meeting your pitch count. This is a great way to save money on one of the more expensive ingredients in your beer.

    Just to note, I used to pitch one pack of dry yeast because that’s what all directions would say. Now, I take that same pack of yeast and make a ton of yeast from it first. Beer made with that extra amount of yeast comes out cleaner than just single packs. It really pays off on lager yeast when it’s over $5/pack and you need at least two. And then, you have plenty of liquid yeast for later.

  94. jrhammonds on

    I’m confused as to why there is such concern about cell count. Correct me if I’m wrong, but as long as you are ‘stepping up’ each of the mason jars (e.g., 2L starter from the slurry yeast in the bottom of the mason jar) yeast cell count should not be an issue, right?

    In other words, the amount of cells you throw into a 2L 1.040 stir plate starter will result in roughly the same amount, regardless of the slurry amount you began with. Granted, a lower original yeast cell count may lead to stressed yeast outcomes, but that shouldn’t be a problem as long as you decant your starter.

  95. Gameface on

    Used this method recently. I like it. I’ve been too paranoid and too adverse to all the extra effort of harvesting yeast from the fermentor. This is easy and super quick.

  96. Peruvian802 on

    Great idea. I’m going to try this with dry yeast (US05) to stretch the cost of a sachet over several batches. Much easier than washing and it doesn’t matter if you are making a lighter or darker beer next. If I make a 3 cup starter, I can save 1/2 pint for the fridge and still have 2 cups to pitch.

  97. jaydog2314 on

    Going to be harvesting some Conan yeast from Heady soon and was wondering…If I make a 2L starter could I just break that up into four 500ml jars, then used a jar to make another starter when I’m ready to brew? then leaving me 3 others for future brews? I’m assuming it’s no different. I just know I plan on getting fresh Heady and want to drink and harvest them asap but won’t brew with it for a few weeks or months.

  98. Brulosopher on

    @jaydog2314 – Just be sure to build up a good amount initially (multi-step) and I don’t see why this would be an issue at all.

  99. samandbekah on

    This is excellent! I have washed yeast a few times but got to say I agree, pain in the butt.

    I’m totally doing this with my next starter, such a great idea Brulosopher, once again another exciting reason to love this hobby!

  100. MNBrewDad on

    Thanks a million Bru! Made my first starter and decided to step it up in order to have some left over for another batch after reading your article. Woke up this morning and five hours after pitching the krausen was pushing its way out of the top of my new 2L flask. Definitely need a larger one for next time or at least some fermcap. Amazing how fast the 2nd step kicks off! I don’t even have a stir plate yet so I’ve been using the intermittent shaking process and those little buggers are going crazy.

  101. starsman20 on

    @Brulosopher I started doing this before finding this post but with one small difference. I always make a starter anyway and I was getting ready to pitch a wlp-001 and saw the vial sitting there and thought why not just pour some slurry back into the vial. Washed the vial with some starsan, decanted off most of the liquid (I always cold crash), sloshed it around a little and poured the first part off into the vial, capped and refrigerated. The longest I’ve let this sit is about 4 months but had no problem after that time of getting a new starter up. The label matches too.

  102. Brulosopher on

    @starsman20 – Makes good sense to me. The only difference I can think of is that I’m harvesting more yeast since I’m pouring it into a larger vessel.

  103. Zoidberg on


    Not neccessarily more yeast since starsman20 is first cold crashing and decanting he could theoretically put all the yeast slurry from a 1 liter starter into the vial. I am currently doing basically this but with 50ml Centrifuges, some of them I’m combining with Glycerine for freezing.

  104. jbags5 on

    Let me just add my thanks to the 100’s of others.

    I haven’t tried this yet, but I do wash my yeast regularly. I get good results, but the idea of basically washing the yeast from the starter wort makes sense and seems a lot cleaner than washing it after a full fermentation.

    You’ve opened my eyes, and I’m going to have to try this technique next time I use a new Yeast packet. Cheers!!

  105. grv on

    I’m giving this a try as we speak with some Wyeast 1469 (Yorkshire) and 1764 (Pacman).

    I do have one question – during the first step, there just appears to be the “beer” on top and the creamy white yeast on the bottom. I do need to keep the yeast longer than is suggested in this state, so I went ahead and did the final steps. When I do this, I end up with three layers – the water on top, then two layers of material, one light one dark. On the 1469, the dark is on top, which is weird. On the 1764 it’s on the bottom.

    Is the dark layer mini-trub? Should I worry about it? In your final pics, it’s not totally clear, but I think I can see a similar dark layer on top of the yeast.

    Thanks for any advice!

  106. CrystalShip on

    great article!

    I’ve done this multiple times with much success. I’ve noticed that the starters I’ve made from the previously harvested yeast look like they contain more yeast than ones made from fresh smack packs.

    Also, I recently made a starter from a jar I had sitting in the fridge since june 1st and the starter fermented a batch with vigor and no off flavors. I did not add it to the smaller jar of water, just left it in the original starter beer for about 2.5 months.

    This is a wonderful method. Thanks for introducing me to it

  107. Redbow on

    I am new to brewing and had considered “washing ” used yeast but when I was actually faced with doing it, it seemed fraught with problems so I dumped the yeast. This makes alot more sense to me – growing up the pure yeast and then reserving some of the pure stuff for the next batch. Alot like saving seed for gardening next year.

  108. ajandrs on

    I have envisioned doing this this for a while now but haven’t pulled the trigger so I’m glad to find someone doing it with success. I’ll be doing this for now on with all my beers.

    One question: to eliminate any proteins / micro trub and the need to decant and add to sanitized water, could this exact process be done with priming sugar? Doing it with priming sugar seems like you would get a solid fermentation without all the byproducts of wort. Plus once it’s done you can just pour it into a clean mason jar and be done with it. perfectly clean yeast cake under perfectly clean and sterile water.


  109. ewebb on

    I was considering if this was a feasible way to harvest yeast during my brew day this coming weekend. Good to see i’m not crazy!

  110. bfinleyui on

    Just did this for the first time a few weeks ago from one-week expired WLP051 yeast, and it turned out great! Thanks! Much easier than washing

  111. brettg20 on

    Wow, seriously why have I been washing yeast all this time?!?
    I figure now that I will save $300-400 a year in yeast…I brew 5 batches a month. All I need to buy was a bigger flask.

    I do have one question. For long term storage (maybe 2-3 months before using to make a new generation of starters), is it beneficial to transfer to the 1/2 pint jars? I don’t mind picking up a case of them but if there is no benefit I have enough pint jars and space to keep a lot…

    Cheers on the write up

  112. scottvin on

    I did this with my 1450 yeast last month. I got very clean water with a nice layer of yeast at the bottom. I used this yeast to make a new starter (and another batch of harvested yeast) and pitched it in a batch yesterday.

    Fermentation was going pretty well this morning!

  113. Keith Hartley on

    Harvested a white labs last week, worked great. Thank you
    My closest brew store is 3.5 hrs away & fermentis dry yeast is about $4.50 a packet.
    Could we do the same with a dry yeast & would it be worthwhile?

  114. balcasaurus on

    Great post! I am brand-new to AG brewing and just got going with my first yeast starter. I was planning on putting in the 1L batch, but then I got to wondering if I could split it, and came across this post. Is it possible to get a decent yield from a 1 liter starter that has been split? I was thinking I could possibly pitch 3/4 of my yeast into the brew I had been planning on and then save 1/4 from that batch to cultivate a new starter. Does this sound like a stretch for the yeast, or viable? FWIW, I am using White Labs 001

  115. HomebrewPadawan on

    I just finished taking the dregs of 3 Bells Pale Ale bottles, growing those yeasties in a mini starter, stepping up that starter, and now I am going to use this technique to get 4 “vials” of the stuff!
    Bells Pale Ale clone…here I come…

  116. jrfehon on

    To add my results to this, I’ve been using 50 billion cells as my standard count when making a new starter from a harvested jar. I don’t have anything scientific to back this up as a good number but the flavors are spot on in my beers and they all take off within 12 hours of pitching. I should note, however, that I haven’t let a jar last more than two months. Again, it’s not scientific but if we all start posting results with what we used as a starting cell count for our harvested yeast we might be able to nail a number down.

    BTW – Brulosopher, you’re the man for posting this! You’ve saved a lot of money for all of us!

  117. ParadoxGuitarist on

    According to the WhiteLabs website, harvesting your own yeast is encouraged for approx 10 generations. After that the yeast starts to mutate/degenerate.

    There should be less yeast fatigue with the method described here since the yeast isn’t exposed to long periods of Alcohol and Carbon Dioxide So maybe double that if you never actually harvest from washing or get any infections?

    You can read the source for yourself here:

  118. thenson801 on

    Back in Nov. 2012, @bierzwinski said “I brew two 12 gal batches at a time, therefore 4 carboys. Using this method, I have one left over to make more starters with.”

    How many more starters can you make from that one leftover? How many times can you repeat this process?

    It’s brilliant! I’m going to be brewing next week, so I’m definitely going to try this!!

  119. Gmull70 on

    Im just wondering do you think that the .5 liter extra starter that you make is equal to a vial of white labs?

  120. irishrover32 on

    is it ok to go straight into a 2.5L starter with one of them 1/2 pint jars or should you start lower and step up??

  121. cpa4ny on

    Thanks Bru – I stay in Singapore and offerings by Wyeast and White Labs are sold by local LHBSs here for about USD 15 (yes, fifteen US dollars – no typos here). Your method really helps to keep the costs under control.

  122. bionut on

    An even better alternative is using isotonic solution (water and salt) instead of plain water. In isotonic solution the yeast can the stored for years at room temperature.
    NaCl solution can be bought from drug stores for cheap or you can make it at home with water and 0.9% table salt, so 9 grams of salt for every litre of water.

  123. bigken462 on

    Having followed the directions listed above using the sterile water from the second smaller jar and keeping this is the bottom of the fridge, would there be a safe guess as to how long this would be good for after the second washing?


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