Pitching Dry Yeast v. Rehydrating

Discussion in 'Homebrewing' started by CCW, Oct 1, 2012.

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  1. CCW

    CCW Initiate (0) May 14, 2012 California

    I am making my first attempt at homebrewing this weekend with a honey nut brown ale. I have safale us 05 ale dry yeast. I have read that some people directly pitch the yeast into the wort and that some prefer to rehydrate via a yeast starter before they pitch it as they believe you loose a substantial amount of yeast cells. From what I've read it seems that rehydrating the yeast is the way to go but I'm curious to know what everyone's experiences and results have been using either method. Happy Brewing and cheers!
  2. Tebuken

    Tebuken Aspirant (286) Jun 6, 2009 Argentina

    There is no need to make a starter, just boil 110 ml for 11 grs dry yeast,let it cool to 96 F then add yeast and wait 15 min.That´s the way yeast is rehydrated.After 15 min you could stirr it up with a sanitized spoon and dump to fermentor.It is always preferable to rehydrate before pitching.
  3. kaips1

    kaips1 Initiate (0) Feb 20, 2011 Kentucky

    either way works, depending on how many living cells are in your packet and your brewing efficiency there shouldnt be a problem pitching it straight, I tend to make starters these days because i can time it pretty right and will get activity in my airlock by the time i go to sleep on brew day.
  4. luisfrancisco

    luisfrancisco Initiate (159) Dec 1, 2009 Mexico

    I used to rehydrate until I started just dumping the dry yeast packets into the fermentor and saw no change at all. When I use liquid yeast, then I'll make a starter, but not for US-05.
  5. VikeMan

    VikeMan Meyvn (1,451) Jul 12, 2009 Pennsylvania

    Rehydration is not the same as making a starter. You probably know that, but I mention it for the OP.

    OP: by some estimates, you'll lose half of your otherwise viable cells by pitching dry yeast without rehydrating. Rehydrating is what Tebuken described. (A starter is something else, and is not generally recommended with dry yeast, for reasons you really don't need to worry about for your first batch, since you are using dry yeast.).
    Mac-daddy likes this.
  6. jtmartino

    jtmartino Disciple (317) Dec 11, 2010 California

    Can you explain why this is the case?
  7. hopfenunmaltz

    hopfenunmaltz Meyvn (1,377) Jun 8, 2005 Michigan

    Dry yeast has the cell membranes full of sterols so they can reproduce for many generations. Dry yeast also has about 20 billion cells/gram so there are 220 billion cells in a fresh 11 gram pack vs 100 billion for liquid yeast. Not much need for a starter.
  8. VikeMan

    VikeMan Meyvn (1,451) Jul 12, 2009 Pennsylvania

    Basically dry yeast is cheap, and comes with more cells per package. And even if you need more cells than come in one package, it's cheaper and easier to pitch two packages than to make a starter.

    Also, at least one dry yeast manufacturer stresses that their yeast is dried in an optimal ready-to-go state that you shouldn't mess with.
  9. beer272

    beer272 Initiate (0) Sep 23, 2009 New Jersey

    I have used dry yeast to date. May change when I go towards AG. I have re-hydrated a couple of times, and more times just tossing it into the wort. I have even drank one of my beers out of glass, then swirl the remnants in the bottle and pitch with just that. That works too, however that slows down the ferment start time. These days I am making starters with bottle dregs.
  10. MLucky

    MLucky Initiate (0) Jul 31, 2010 California

    Whenever you ask a question like that around here, you will always hear from people on both sides who say their beer comes out great. And that's probably true: beer can be pretty forgiving. But in my mind brewing is all about adopting the best practices and doing things right, and in this case that would be rehydrating. If you don't, you will indeed lose cells, and you will have a less than ideal pitch rate. The yeast will still make beer, but they'll be more stressed, and that can result in off flavors.

    One thing that can be a little tricky for a first-timer: you want to pitch the yeast roughly 15 minutes after it's been rehydrated. If you wait longer, the rehydrated yeast can actually 'starve' before you pitch. When it's your first time or two, it can be difficult to know how long it's going to take to cool the wort to pitching temp. So here's my unsolicited advice: wait till the wort is cooled, then rehydrate, then pitch. Don't pitch while cooling. Good luck!
    pwoods2122 likes this.
  11. jtmartino

    jtmartino Disciple (317) Dec 11, 2010 California

    Understood - so it's less of a viability or quality issue, and more of an economic standpoint. Thanks.
  12. billandsuz

    billandsuz Disciple (364) Sep 1, 2004 New York

    this comes up quite a bit. the answers posted so far are spot on, so i will summarize.

    the factual answer, if not always the practiced method, is that dry yeast should be rehydrated in blood warm water for 5 to 15 minutes before pitching. "proofing" dry yeast will result in a substantially larger colony at pitching. (pitching unhydrated yeast into wort needlessly, sadly and mercilessly kills perhaps 30% upon impact. don't be a yeast killer!)

    a starter is not needed with dry yeast. it is not even required or recommeded. not by brewers or dry yeast producers.

    liquid yeast is more delicate than dry yeast and requires special attention.

    dry yeast has been dried with a full store of oxygen and is "ready to go".

    dry yeast is relatively cheap. if you think you need more, buy another package.

    lastly, it is worth mentioning that dry yeast has a best by date. stale or mistreated yeast is not worth the cost savings.

    so, rehydrate two packages and pitch. sleep well.
  13. mikehartigan

    mikehartigan Disciple (328) Apr 9, 2007 Illinois

    Dry yeast that has been properly stored and handled can be pitched dry without ill effect. There are those who will disagree with that purely on the premise that rehydrating must be better. People who insist that the result is superior have likely never pitched dry or had another problem that had nothing to do with the dry pitch. I'm not aware of any controlled tests that show a benefit to rehydration. Indeed, there's a link somewhere in which someone did an A-B experiment, and the differences were unremarkable. I'll try to find that link. Estimates of a 50% kill rate may or may not be true, but there's plenty left to do the job just fine. Terms like 'Best Practice' are frequently tossed around, but that doesn't apply here (Best Practice is defined a method or technique that has consistently shown results superior to other methods. That hasn't been done with rehydrated dry yeast). It can be argued that it's a safer bet, to mitigate bad storage practices, but that's typically not an issue. It's 'better' in the same sense that carrying two spare tires in your car's trunk is 'better' than carrying one.
    Pitch it dry. You'll be fine.
    utopiajane and depechemode1983 like this.
  14. Homebrew42

    Homebrew42 Initiate (165) Dec 20, 2006 New York

    It's not an estimate, it's been measured, this is not difficult to do as it only requires very basic lab equipment. During rehydration yeast cells cannot regulate what comes across their membranes, and when rehydrated in wort sugar comes rushing into the cells at toxic levels.
  15. mikehartigan

    mikehartigan Disciple (328) Apr 9, 2007 Illinois

    That's fine, but irrelevant, since, as I said, there's plenty left even after the slaughter. How many spare tires do you carry? ;-)
  16. cmmcdonn

    cmmcdonn Initiate (0) Jun 21, 2009 Virginia

    If you make a bigger beer and do this, you may end up underpitching. I believe this makes it relevant.

    I'm sure tossing yeast in dry will work 90% (or more) of the time, but rehydrating is such an easy step, I don't know why anyone would intentionally choose to ignore it.
  17. tngolfer

    tngolfer Initiate (0) Feb 16, 2012 Tennessee

    Fermentis recommends both ways to pitch on their website. They do list rehydrating first so I took that as a hint and I rehydrate 90% of the time.

    Pitching instructions: Re-hydrate the dry yeast into yeast cream in a stirred vessel prior to pitching. Sprinkle the dry
    yeast in 10 times its own weight of sterile water or wort at 27C ± 3C (80F ± 6F). Once the
    expected weight of dry yeast is reconstituted into cream by this method (this takes about 15 to
    30 minutes), maintain a gentle stirring for another 30 minutes. Then pitch the resultant cream
    into the fermentation vessel.
    Alternatively, pitch dry yeast directly in the fermentation vessel providing the temperature of
    the wort is above 20C (68F). Progressively sprinkle the dry yeast into the wort ensuring the
    yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes
    and then mix the wort e.g. using aeration.
  18. CCW

    CCW Initiate (0) May 14, 2012 California

    The rehydration process seems fairly simple provided the timing is right, althought I'm not sure if I will rehydrate the first go around. I'm thinking it may be better for me to pitch the yeast dry and figure out the whole cooling time/brewing process a little more so I'll have a better understanding of the timing needed. I'm thinking to compensate for dry pitching cell loss that I'll pitch an additional pack.
  19. VikeMan

    VikeMan Meyvn (1,451) Jul 12, 2009 Pennsylvania

    Does anyone have a source for this idea that the yeast will starve after 15 minutes? I would think they will start to slowly die off, just as a liquid yeast population would if you sit it on your counter at the same temperature, or in the fridge (much more slowly). But what's special about dry yeast that they will almost instantly bite the bullet?
  20. mikehartigan

    mikehartigan Disciple (328) Apr 9, 2007 Illinois

    I won't disagree with that. I should have qualified my comments as applying to 'normal' gravity beers. For heavier beers, I either pitch additional packets or, more likely, brew up a five gallon 'starter' and pitch on the cake.
    for me, it's worked 100% of the time I've done it. I rehydrated a few batches years ago and decided it wasn't work the extra hassle, minimal as it is, or the risk. There was a post here a while ago in which it was concluded that rehydrating dry yeast actually creates more problems than it 'solves' (I put 'solves' in quotes, because the problem that it is supposed to address - inferior beer - has not been demonstrated). And I'm a firm believer that, regardless how trivial the effort, not doing it is easier than doing it, particularly if it serves no useful purpose. I don't rehydrate my dry yeast for exactly the same reason I don't twirl three times before getting into my car in the morning.

    That said, even if it brings you nothing more than peace of mind, then, by all means, do it. Placebos can be very effective medicine - if it works, I don't care why.
  21. abraxel

    abraxel Initiate (0) Aug 28, 2009 Michigan

    Both of these make it sound like with dry yeast it's not as important to aerate/oxygenate the wort. Is that the case?

    Edit: I found this on Danstar's FAQ:
    But the rest of the google hits seem to call that into question. Any thoughts?
  22. hopfenunmaltz

    hopfenunmaltz Meyvn (1,377) Jun 8, 2005 Michigan

    You don't need to, but it doesn't hurt.
  23. premierpro

    premierpro Aspirant (238) Mar 21, 2009 Michigan

    I have pitched both ways and in my opinion rehydrating gives you the security of knowing you have proper cell counts. It's not that hard.
  24. abraxel

    abraxel Initiate (0) Aug 28, 2009 Michigan

    Good to know, thanks! I just used dry yeast for the first time a few weeks ago (there wasn't any real reason I avoided it; I just liked liquid yeast better), but now I'm planning to use it whenever I reasonably can. It's so easy!
  25. hopfenunmaltz

    hopfenunmaltz Meyvn (1,377) Jun 8, 2005 Michigan

    I use dry yeast a fair amount, but there are more strains that I like to use in liiquid form. I don't think that making starters is too hard, just takes some planning.
  26. mikehartigan

    mikehartigan Disciple (328) Apr 9, 2007 Illinois

    Here's a link to what has become a legendary exchange on this subject between Dan Listermann and Dr. Clayton Cone, both highly respected and knowledgeable in the field:


    Listermann cites evidence that suggests that rehydrating dry yeast may lead to problems (nobody's technique is 100%). Dr Cone responds by describing the correct procedure for rehydrating dry yeast. Unfortunately, he doesn't answer Listermann's question directly (risk versus benefit). Draw your own conclusions.

    In my search, I found a number of people who conducted perfectly valid experiments, but looking only to document the relative cell counts between different techniques. Most of the conclusions pretty much confirmed the kill numbers that have been cited in this thread and in threads appearing here and on other sites. However, the few that actually extended the experiment through to informal taste testing noted differences in the final product that ranged from subtle to non-existent. Even in those where differences were noted, there was no clear consensus on which was better (much like the olive oil versus aeration experiments though, if I recall correctly, the panel leaned slightly toward the olive oil).

    My own personal bottom line, gleaned both from experience and from opinions expressed by people who have actually bothered to try it both ways, is that, while rehydrating dry yeast generally results in a higher viable cell count (which is not a bad thing), the proof of the proverbial pudding is in the eating. There appears to be no significant differences between the two techniques in terms of the quality of the final product (the only criterion that means anything, IMO). I think it's safe to say that rehydrated dry yeast produces beer that is as good as beer made with dry yeast pitched according to the package directions ("Sprinkle directly into wort", or words to that effect). I don't carry two spare tires, I don't twirl before getting into my car, I don't sit down to pee, and I don't rehydrate my dry yeast. It's that simple.
  27. Homebrew42

    Homebrew42 Initiate (165) Dec 20, 2006 New York

    That's one way to interpret the tasting results, another way is that rehydrating may produce a beer that is subtly different.
  28. billandsuz

    billandsuz Disciple (364) Sep 1, 2004 New York

    i know there are always some homebrewers that would just as soon pitch dry yeast to wort. well, some being Mike. if it works well enough, that is fine and the subject is not even a debate anymore. but,
    i consider myself to be a rather lazy brewer (but a serious drinker) and just don't think filling a cup with warm water and a package of powder is such a burden. why wouldn't we rehydrate the yeast? why risk underpitching? its not like making a starter. it is really just about the easiest thing a brewer could do to improve the initial fermentation. that's my opinion anyway.
    GreenKrusty101 and JackHorzempa like this.
  29. MLucky

    MLucky Initiate (0) Jul 31, 2010 California

    I think I came across this idea a few weeks ago, when I decided to add some champagne yeast to a saison I wanted to dry out. It had been a long time since I’d used dry yeast, so I wanted to review the hydration process, and in doing that I came across a number of statements like the one patched in below, which is from the Morebeer site. One important note: this is from their guidelines for hydrating dry wine yeast.
    “Once the yeast has been introduced into the hydration water, you need to be aware that the clock is ticking. This is because the yeast will soon completely use up whatever stored energy they previously had in them from their preparation at the factory to complete the hydration process. From this point on, if they don’t get the nutrition they need they will quickly begin to starve, deteriorate and begin to lose viability. So, it’s best not to prolong this moment and begin feeding them immediately. Fortunately, the timing of this critical feeding is based on an easy-to-read indicator: once you begin to see signs of activity at around the 20-30 minute mark, then the yeast are letting you know that they now are wanting to be fed and are ready to be exposed to the must. It is important to note that you should never let the hydration process extend beyond 30 minutes without giving them food.”
    Now, whether that is equally applicable to beer yeast, I don’t know. Apologies if I’m spreading false info above. Perhaps somebody here can speak to that question, and to the issue of why rehyrdated yeast may be different in this respect.
  30. CCW

    CCW Initiate (0) May 14, 2012 California

    Those who pitch the dry yeast into the wort, do you add an additional pack or just the one? My guess is that if you don't rehydrate, an extra pack would be a safe bet. Very good article by the way, thanks Mike!
  31. mikehartigan

    mikehartigan Disciple (328) Apr 9, 2007 Illinois

    because it's easier not to
    there's no evidence to suggest that that this is the case
    it's even easier to not do it and there's no evidence that it improves anything beyond, perhaps, peace of mind (and, as I said earlier, there's nothing wrong with that)
    ...and you're entitled to it
    Indeed! :slight_smile:
  32. mikehartigan

    mikehartigan Disciple (328) Apr 9, 2007 Illinois

    Up to maybe high 1.060's, I use a single pack. FWIW, I've won a bunch of ribbons over the years without rehydrating. Granted, that doesn't really prove anything, just tootin' my own horn, is all :wink:
  33. JackHorzempa

    JackHorzempa Poo-Bah (3,637) Dec 15, 2005 Pennsylvania

    The topic of timing for pitching re-hydrated dry beer yeast was recently discussed in this thread: http://beeradvocate.com/community/threads/how-long-to-wait-for-signs-of-fermentation.40810/#post-511825

    You ask: “Is it bad to leave rehydrated dry yeast out of the wort for too long?” Well, ideally you shouldn’t let the rehydrated yeast sit out too long but I am unsure what the definition of “too long” is. You will read below that the benefit of pitching the rehydrated yeast in a timely manner (e.g., 30 minutes) is to permit the yeast to get a quick start to fermenting the wort.

    You also ask: “Would you just need to add sugars of some kind for them to eat?” I am unsure how to respond to this other than the best thing to do is simply rehydrate the dry yeast in warm water and pitch it in a timely manner (e.g., 30 minutes). Would it have been ‘better’ for BikingDutchmn to add some sugar to the rehydrated yeast once it reached the 3 hour point? I really don’t know.

    Now is the time for a more expert person to way in. Below is something that Dr. Clayton Cone (of Danstar) stated which relates to this discussion:

    “We recommend that the rehydrated yeast be added to the wort within 30 minutes. We have built into each cell a large amount of glycogen and trehalose that give the yeast a burst of energy to kick off the growth cycle when it is in the wort. It is quickly used up if the yeast is rehydrated for more than 30 minutes. There is no damage done here if it is not immediately add to the wort. You just do not get the added benefit of that sudden burst of energy. We also recommend that you attemperate the rehydrated yeast to within 15F of the wort before adding to the wort.

    Warm yeast into a cold wort will cause many of the yeast to produce petite mutants that will never grow or ferment properly and will cause them to produce H2S. The attemperation can take place over a very brief period by adding, in increments, a small amount of the cooler wort to the rehydrated yeast.”

  34. jakeaustin

    jakeaustin Aspirant (271) Dec 23, 2007 Maine

    count me as a non-hydrator. Although if I'm using dry yeast it's going into a 3-5% beer. Anything larger and I'm using liquid yeast and a starter, or pitching onto a cake.
  35. JackHorzempa

    JackHorzempa Poo-Bah (3,637) Dec 15, 2005 Pennsylvania

    I re-hydrate my dry yeast since I consider it an easy process and by re-hydrating I am taking steps to optimize the number of viable yeast cells. I do not know if I am making ‘better’ beer by doing this process. I think that Mike Hartigan has a valid point in his statement of: “There appears to be no significant differences between the two techniques in terms of the quality of the final product.”

    There are potential benefits of performing re-hydration such as:

    · Peace of mind in knowing that you are pitching a larger number of viable yeast
    · Potential for a shorter lag time (if that is important to you)
    · Other benefits?

    I suppose I would advise other homebrewers to re-hydrate their dry yeast if they think there is a benefit to pitching more viable yeast.

    As Mike has demonstrated in his homebrewing practices, you can indeed make award winning beers by simply sprinkling the dry yeast on the wort.

  36. JackHorzempa

    JackHorzempa Poo-Bah (3,637) Dec 15, 2005 Pennsylvania

    Another potential benefit of re-hydrating dry yeast: shorter fermentation timeframe.

  37. CCW

    CCW Initiate (0) May 14, 2012 California

    Can you ever pitch too much yeast? As in pitching two packs to compensate for cell loss due to not rehydrating? I am looking into this question as I post...
  38. billandsuz

    billandsuz Disciple (364) Sep 1, 2004 New York

    yes, over pitching can be a problem for commercial brewers. but the consensus is that no homebrewer has ever created a flawed beer due to over pitching. consider too that the once fermentation gets going, the cell count is astronomically high. way higher than what we pitch.

    using two 11g packs of yeast is not going to do any harm.
  39. Homebrew42

    Homebrew42 Initiate (165) Dec 20, 2006 New York

    I used to think this, but after listening to Chris White speak on the subject and doing some experimenting I disagree. It has nothing to do with how much yeast are present during active fermentation and everything to do with how much yeast growth happens in the wort. In other words if you pitch so much yeast that you're seeing active fermentation in 3 hours then you're not getting the proper yeast growth in the wort, and this is when much of your yeast derived flavor is produced. White suggests that the ideal lag time is 12-24 hours, if you're getting longer than this you're probably pitching too little yeast, shorter and you're probably pitching too much.
  40. GreenKrusty101

    GreenKrusty101 Crusader (711) Dec 4, 2008 Nevada

    I have used a shit load of dry yeast over the last 5 years...mostly US-05, but occasionally some Nottingham. The very first batch I made I did NOT rehydrate...every thing since has been rehydrated because it is so easy. This 15 min. and you will die bullshit (paraphrased :slight_smile: is really funny because the rehydration instructions from what I remember say 30 min anyway.

    Now that I'm brewing 10 gal. batches, I'm a lot more busy @ T-15 (boil) so I'm contemplating just using 3 unhydrated sachets and calling it good. I should be able to tell if this change is negatively affecting the beer fairly quick.
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