How long to wait for signs of fermentation?

Discussion in 'Homebrewing' started by BikingDutchman, Sep 25, 2012.

  1. BikingDutchman

    BikingDutchman Aug 9, 2012 Iowa

    I just brewed my first batch and it is sitting in the primary right now. I am concerned that I pitched the yeast too early (I pitched them at 85 degrees because I couldn't get the wort to cool down fast enough) and may have killed them... How long do I have to wait before I see any signs of fermentation in the airlock? It has been sitting for 12 hours at 72 degrees with no visible changes.

    Also, could the yeast have been sitting too long before I pitched them? I re-hydrated them just after I started cooling the wort, but when I ran out of ice, it took the wort 3 hours to cool! I sealed the wort in the primary to prevent infection, but the yeast was sitting at room temp in a saran wrap covered measuring cup for that long.

    Bottom line: I think I made a newbie mistake, and want to make sure my beer will come out okay.
     
  2. RichardMNixon

    RichardMNixon Jun 24, 2012 Pennsylvania
    Beer Trader

    It doesn't sound like anything to worry about yet. Dry yeast usually start slower anyway by my understanding, and if anything, you'd have been better off rehydrating them earlier.
    Don't worry until it's pushing 48-60 hours, then you might need to repitch.
     
  3. premierpro

    premierpro Mar 21, 2009 Michigan
    Subscriber

    Pitching yeast at 85 degrees is not the best practice. ( I have done this before. ) You still should be fine. I start geting nervous at the 24 hour mark. I have had beers start after that and blow the lid off. Check and make sure your seal is tight and you have enough fluid in your air lock. You will make more mistakes if you continue this hobby,however it is hard to screw up a batch.
     
  4. BikingDutchman

    BikingDutchman Aug 9, 2012 Iowa

    Given that I use dry yeast again for my next batch, how long should I let it hydrate before pitching?
     
  5. Homebrew42

    Homebrew42 Dec 20, 2006 New York

    85 degrees is too warm to pitch, but not because it will kill the yeast, because it will cause the yeast to produce off flavors.

    That said, 12 hrs is not that long, it's not unusual for it to take 24-36 hours. Also, airlocks sometimes don't tell the entire story, buckets will often leak and allow gas to escape from elsewhere and the airlock won't bubble. In cases Ike this if you open the bucket and look inside you will see krausen, which means active fermentation is taking place.
     
    GreenKrusty101 likes this.
  6. BikingDutchman

    BikingDutchman Aug 9, 2012 Iowa

    I knew that 85 was way too warm, I just didn't want the yeast sitting out too long and I wanted to pitch before I went to bed. I heard that it can produce banana flavors? I'm making a dunkelwiezen, so hopefully these banana flavors won't clash much.
     
  7. ventura78

    ventura78 Nov 22, 2003 Massachusetts

    One of the first beers I ever made had a lot of banana flavor in it.,,,,it was good.
     
  8. VikeMan

    VikeMan Jul 12, 2009 Pennsylvania
    Beer Trader

    In general it will make lots of esters, which may or may not include increased banana. It may also make fusel alcohols.
     
  9. JackHorzempa

    JackHorzempa Dec 15, 2005 Pennsylvania

    “ …how long should I let it hydrate before pitching?”

    Each vendor provides recommended procedures for rehydrating their yeast. Below is information from Fermentis for US-05 and Danstar for Windsor. I personally rehydrate for 15-20 minutes in a cup of warm water (temperature per the vendor’s instructions) and I attemperate over a time duration of a few minutes.

    Fermentis US-05 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.

    Danstar Windsor yeast instuctions:

    • Sprinkle the yeast on the surface of 10 times its weight of clean, sterilized (boiled) water at 30–35°C.
    Do not use wort, or distilled or reverse osmosis water, as loss in viability will result. DO NOT STIR.
    Leave undisturbed for 15 minutes, then stir to suspend the yeast completely, and leave it for 5 more minutes at 30–35°C. Then adjust temperature to that of the wort and inoculate without delay.
    • Attemperate in steps at 5-minute intervals of 10°C to the temperature of the wort by mixing aliquots of wort. Do not allow attemperation to be carried out by natural heat loss. This will take too long and could result in loss of viability or vitality.
    • Temperature shock, at greater than 10°C, will cause formation of petite mutants leading to long-term or incomplete fermentation and possible formation of undesirable flavours.
     
  10. RichardMNixon

    RichardMNixon Jun 24, 2012 Pennsylvania
    Beer Trader

    Whoops, I guess I figured it'd be analogous to a yeast starter. Is it bad to leave rehydrated dry yeast out of the wort for too long? Would you just need to add sugars of some kind for them to eat?
     
  11. JackHorzempa

    JackHorzempa Dec 15, 2005 Pennsylvania

    The OP stated in his first post: “Also, could the yeast have been sitting too long before I pitched them? I re-hydrated them just after I started cooling the wort, but when I ran out of ice, it took the wort 3 hours to cool!”

    I purposefully didn’t comment on the aspect of him letting the rehydrated yeast sit for 3 hours since I am uncertain what the effects are of this time duration.

    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.”

    Cheers!
     
  12. BikingDutchman

    BikingDutchman Aug 9, 2012 Iowa

    Thanks for your help, everyone. I guess I just know what to do better next time.
     
  13. HopNuggets

    HopNuggets Oct 8, 2009 Connecticut

    I have read when rehydrating dry yeast you don't want to leave them in water much longer than 30 minutes as they start to starve. 3 hours may have been a bit long. I don't rehydrate dry yeast, I just pitch them in and have never had issues with that practice. Time for a wort chiller my friend.
     
  14. goodonezach

    goodonezach Mar 24, 2011 New York

    or if you don't want to get a wort chiller just yet (you'll eventually need one when you start doing full-volume boils) just get it as close as possible to pitching temp, then put it wherever you're going to ferment it and let it cool overnight. it's more important to pitch at the right temp and make sure you get a good fermentation than it is to just get the beer done asap, because even if you make a great recipe, fermenting it too high will make some serious off flavors that can be difficult to hide, not to mention fusel alcohols. once you get past the novelty of drinking beer you made, you're going to hate the hangover that beer gives you when it ferments too hot.
     
  15. RichardMNixon

    RichardMNixon Jun 24, 2012 Pennsylvania
    Beer Trader

    I am by no means an expert, but I don't think I agree. The longer the wort sits there without the yeast, the more likely it is to be infected. Certainly putting it in the carboy would help, but I still think you want the yeast in there ASAP so they can outnumber the bacteria.
     
  16. Homebrew42

    Homebrew42 Dec 20, 2006 New York

    I'd rather wait a few hours, get the beer down to a proper pitching temp, and take the infinitesimal risk of infection than pitch at 85 degrees and take the large risk of fusels, acetaldehyde, and other off flavors.
     
  17. RichardMNixon

    RichardMNixon Jun 24, 2012 Pennsylvania
    Beer Trader

    I guess it depends on how many hours.

    Would you still consider those odds infinitesimal? 8-12 hours seems a pretty long time to me.
     
  18. GreenKrusty101

    GreenKrusty101 Dec 4, 2008 Nevada

    Yes...8-12 hours is not a long time for yeast...shit, it takes much longer for bacteria to multiply...assuming you did at least a mediocre job of sanitation : )
     
  19. JackHorzempa

    JackHorzempa Dec 15, 2005 Pennsylvania

    “Would you still consider those odds infinitesimal? 8-12 hours seems a pretty long time to me.”

    There is really no way to quantify that since that is highly dependent on the efficacy of the sanitation process.

    A number of years ago I conducted a check on my sanitation practices by taking a portion of my wort and keeping it in a similarly sanitized jar to see if there would be signs of infection over a period of several days. I would look for signs (bubbles, film on top, etc.). After 3-4 days I tasted it for off flavors. Even after 3-4 days there were no perceptible off flavors. I did this for a few batches and I consistently did not obtain perceptible signs of infection. This gave me confidence that I was practicing effective sanitation in my brewing practices.

    So, based upon my experiences with my sanitation practice I would not be overly concerned about having wort sit for 8-12 hours. Having stated that, my homebrewing process is to cool my wort down to pitching temperature in less than 30 minutes and pitching my yeast at the 30 minute mark.

    Cheers!
     
  20. RichardMNixon

    RichardMNixon Jun 24, 2012 Pennsylvania
    Beer Trader

    Cool, thanks! Good to know.
     
  21. Homebrew42

    Homebrew42 Dec 20, 2006 New York

    It shouldn't take 8-12 hrs to bring your wort down to an acceptable pitching temp. At the very least you can put it in a bathtub full of cold water and you'll have an acceptable temp in an hour.
     
  22. goodonezach

    goodonezach Mar 24, 2011 New York

    i'm getting this from jamil z. who is an expert. he says the odds are really non-existent unless your sanitation practices aren't up to snuff.
     
  23. GatorBeer

    GatorBeer Feb 2, 2010 South Carolina
    Beer Trader

    48-72 hours until I'd worry.
    Take a hydrometer reading, airlocks aren't meant to be a judge of fermentation.
     
  24. BikingDutchman

    BikingDutchman Aug 9, 2012 Iowa

    I don't have a hydrometer as this is my first batch. (guy at the homebrew store said I wouldn't need one for a kit... I shouldn't have listened) t-36 hours with no signs of fermentation.
     
  25. JackHorzempa

    JackHorzempa Dec 15, 2005 Pennsylvania


    “t-36 hours with no signs of fermentation.”

    The airlock is not always a good indicator of fermentation starting. There is the potential for issues such as:

    · If it is a 3-piece airlock, did you fill up to the water line?
    · Is the lid sufficiently snapped down (assuming you are using a bucket). Maybe there is some leakage through the lid?

    Did you inspect for the presence of krausen (a layer of foam) on top? Maybe you could take a quick peak and see if some krausen if being formed?

    Personally I would have expected some sign of fermentation at this point in time. Maybe give it another day but in the mean time you might want to purchase another pack of dry yeast in case you need to add more yeast.

    Here is something I posted a few days ago which relates to this discussion: http://beeradvocate.com/community/threads/almost-4-days-later-and-no-fermentation.39914/#post-499982

    Cheers!
     
  26. BikingDutchman

    BikingDutchman Aug 9, 2012 Iowa

    I looked for krausen as well, and there was none. If I pitch another pack of yeast, what are my chances of having an infected batch?
     
  27. Homebrew42

    Homebrew42 Dec 20, 2006 New York

    Did you open the bucket and look inside?
     
  28. Homebrew42

    Homebrew42 Dec 20, 2006 New York

    Low.
     
  29. JackHorzempa

    JackHorzempa Dec 15, 2005 Pennsylvania

    “If I pitch another pack of yeast, what are my chances of having an infected batch?” Your chances of having signs of infection (i.e., off flavors) is highly dependent on your sanitation process. If you practiced good sanitation then your wort should be OK.

    At this point I would recommend that you just add another package of dry yeast. Just keep it simple: sprinkle the dry yeast on top of your wort and whip it up in stirring as an aeration method.

    Chances are that this batch will turn out fine (assuming good sanitation was exercised).

    Cheers!
     
  30. tjensen3618

    tjensen3618 Mar 23, 2008 California

    I don't get this about pitching high...

    Last night I pitched high, really high 90f. It's not gonna kill the yeast and the temp will be down to 70f within a couple hours before active fermentation really starts. How much fusels and esters am I really gonna pick up in the couple hours from when I pitched to when it's cooled to appropriate fermentation temp?
     
  31. Homebrew42

    Homebrew42 Dec 20, 2006 New York

    Those first few hours, when the yeast are actively growing and dividing, are when most esters and other flavor compounds are formed, not during active fermentation. The first few hours are in fact the most critical, this is why pitching too much yeast can cause a beer to be bland, because you're attenuating the growth phase, and why under pitching can cause off flavors, because you're extending the growth phase.
     
    mathematizer likes this.
  32. JackHorzempa

    JackHorzempa Dec 15, 2005 Pennsylvania

    You mention: “Those first few hours, when the yeast are actively growing and dividing, are when most esters and other flavor compounds are formed, not during active fermentation.”

    I have seen this stated before. I would very much like to learn more on the topic of yeast growth phases and what occurs during those phases with respect to the production of flavor compunds. Do you have any articles or books that you can recommend (or provide links to) that discuss the above?

    I tried to do some research via web surfing with some limited success. I found a reference to the book Brewing Science and Practice by Briggs, Boulton, Brookes and Stevens. That book is available on Google Books. In a series of graphs in Figure 12.1 (pg. 403) there is a graph which illustrates the production of higher alcohols, esters and vicinal diketones (VDK) over time. The total values of these three peak at around:

    · VDK: 60 hours (2.5 days)
    · Higher Alcohols: 75 hours (3.125 days)
    · Esters: 100 hours (4.167 day)

    This graph seems to indicate that flavor compounds are still very much being produced during the active fermentation phase.

    Cheers!
     
  33. BikingDutchman

    BikingDutchman Aug 9, 2012 Iowa

    I repitched more dry yeast directly into the primary at 60 hours. Crossing my fingers now that I may have saved the beer.
     
  34. GatorBeer

    GatorBeer Feb 2, 2010 South Carolina
    Beer Trader

    Can we have an "Ask Homebrew42 Anything" thread stickied because he always nails the answers succinctly and accurately every time. Cheers
     
  35. hopdog09

    hopdog09 Sep 6, 2012 Michigan

    I always make a starter with my dry yeast 24 hours ahead of time, about a 750ml for 5 gallons, this gives me a visual that the yeast is in fact working and doing its thing. I get active fermentation within 4 hours usually...fermentation anxiety sucks.
     
  36. Gsa1984

    Gsa1984 Oct 7, 2014

    Stumbled on this thread from a google search. I just made my first batch of home brew. Basically I did all the same things as BikingDutchman. Now I'm having the same issues. My question is this. Is it normal for the yeast to settle at the bottom of the fermenter? It has only been a few hours.
     
  37. jbakajust1

    jbakajust1 Aug 25, 2009 Oregon
    Moderator Subscriber

    Probably not yeast settling at the bottom. It is probably trub, especially if you can see the layer as the initial pitch from a packet of commercial yeast isn't large enough to see at the bottom until after fermentation has occurred. The trub is the proteins formed during hot break (just before the boil hits) and cold break (during the chilling process), and hop particulate (especially with pellets). I would give it another 24 hours, bring the BEER temp down into the mid 60s, and get a fresh packet of yeast just in case there is no fermentation activity after 36 hours.
     
  38. FATC1TY

    FATC1TY Feb 12, 2012 Georgia
    Moderator Subscriber Beer Trader

    Interesting this thread popped back up. I did a bit of an experiment if you will this weekend. Not a direct comparison, but shows the amount of work needed to make yeast happy, which result in.. well better results and worrying.

    I brewed a batch of IPA on Saturday. I pitched two vials of Vermont Ale into a 1L starter earlier in the week. Both had gone past the "best by" date on the vial. I got quick activity and plenty of yeast. I stepped it up again to 1.5L and had no issues. Crashed it for two days, decanted it, swirled and pitched into my wort at 60*. Allowed it to free rise to 63* and held. I had activity in under 8 hours.

    Brewed a similar grist, similar gravity IPA on Sunday. Decided to see the difference. I pitched two vials into the wort, no starter, and both those vials were around 90 days from their best by date. Same procedure.. Took over 24 hours for me to see signs of krausen. Did see some bubbling in airlock, but no krausen or churning in the fermenter.

    While the second batch is JUST not getting going, the other batch is winding down and finishing up it's fermentation. Krausen is starting to drop and beer it slowing down.

    The second batch started fermenting right around the time my sour stout did, and the sour stout was indeed underpitched for a reason.

    Point is.. Pitch healthy amounts of yeast, aerate it correctly, and control the temp BEFORE you pitch and while it's fermenting.
     
    Mothergoose03 likes this.
  39. koopa

    koopa Apr 20, 2008 New Jersey
    Beer Trader

    Most of the materials I've been studying in brew school also seem to suggest that these compounds are not as much produced during the initial lag phase as they are during primary fermentation (growth phase and stationary phase) although I'm sure its possible that the development of some of the precursors and catalysts to the production of such compounds starts during the lag phase to some degree. It's my general understanding that yeast first focuses much of its effort on reproducing and that, when the majority of growth is complete, more energy is then spent on producing these compounds. It's not a 100% clean dividing line though, as the two processes do bleed over to some degree. For example, higher alcohols are predominantly produced by yeast synthesizing amino acids in an effort to promote yeast growth. But when you restrict yeast growth for example, the yeast get an earlier start on shifting there efforts towards ester production so limiting yeast growth can result in higher ester production.
     
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