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How Long is Too Long in Primary Fermenter?

Discussion in 'Homebrewing' started by emilystrikesagai, May 30, 2012.

  1. I've got a Brewers Best kit Belgian Caramel Wit in my primary for about 4 weeks - I've been out of town and busy with work and just haven't had time to bottle.

    I'm pretty new at brewing and up until now have always. followed. directions (BB kits say 2 weeks but I think that's kind of soon).

    What can I expect? How long is too long if I bottle it tomorrow night?
  2. VikeMan

    VikeMan Champion (930) Pennsylvania Jul 12, 2009 Verified

    Most folks would say that 4 weeks is not too long, given healthy yeast and reasonable temperatures in a homebrew setting. Some people routinely go 4 weeks or even longer.
  3. Good to hear! Interesting that kits would say 2 weeks then. Is that to oversimplify it?

    I'm going to bottle it and drink it anyway, I just wanted to understand any problems I may encounter.
  4. “Interesting that kits would say 2 weeks then. Is that to oversimplify it?” Well, in all probability the fermentation of that beer was completed in 2 weeks. Some folks like to leave their beers in the primary for ‘extra’ time to obtain the benefits of ‘maturing’ during this additional bulk conditioning time.

    To get back to the specific question of “How Long is Too Long in Primary Fermenter?” The principle concerns for extended time in a primary fermenter are yeast autolysis and the potential for oxidation if you are using a plastic fermenter.

    The risk of yeast autolysis (the ‘breakdown’ of the dormant yeast) is debated amongst homebrewers. The conventional rule of thumb was (is?) to not let your beer ‘sit’ on the dormant yeast for more than 4 weeks. The timeframe of 4 weeks is not ‘cut and dry’ but it would be wise to not let the beer ‘sit’ on the dormant yeast for months.

    A plastic bucket primary fermenter is not impermeable to oxygen. Over time oxygen will pass through the plastic walls and start oxidizing the beer. There is no ‘cut and dry’ rule for this timeframe but I have seen where some folks mention 4 week as well (maybe to be consistent with the yeast autolysis timeframe?). If your primary fermenter is a glass carboy (or a Better Bottle) than there is no concern with respect to oxidation (glass and Better Bottle material are impermeable to oxygen).

    So, in summary having your beer in the primary for 4 weeks is OK. It is likely you could keep it in the primary for a few more weeks (if events made that happen) that would likely be OK as well. I would suggest that something like 2 months in the primary is too long but that is just my humble opinion.

  5. VikeMan

    VikeMan Champion (930) Pennsylvania Jul 12, 2009 Verified

    Kit instructions are often not worth the paper they are printed on. If you wanted to sell kits to new brewers, would you rather put 'ready in 3 weeks' or 'ready in 6 weeks' on the box?

    What you really want to do is make sure attenuation is finished, then give the yeast a little more time to clean up their byproducts. Beyond that, extra time on the yeast isn't necessarily helping, but (within reason) isn't hurting either.
  6. epk

    epk Savant (360) New Jersey Jun 10, 2008 Verified


    It actually appears to suggest a total of 3 weeks in the side bar. 5-7 days primary and 2 weeks secondary (though step 10 contradicts that).

    Secondary has fallen out of style with many homebrewers (unless it's necessary to dry hop or add other flavoring). A lot of us will just primary 4 weeks, as you did. 4 weeks gives the yeast time to do some clean up. If you can, you might want to take a gravity reading (though if all went fine, it's defiantly done).
  7. Yep, that's the one! All their kids suggest using a secondary but my home brew shop told me it was unnecessary, so I've never done it. I've previously stayed true to the 2 week instructions.
  8. yinzer

    yinzer Savant (395) Pennsylvania Nov 24, 2006

    Yes given healthy yeast. But if you pitch dry yeast without re-hydrating and half of the yeast dies as soon as it hits the wort, then it's not very healthy. JZ feels that is were the raking all beers to the secondary came from.

  9. “I've previously stayed true to the 2 week instructions.” It is possible to debate 2 weeks vs. 3 weeks vs. 4 weeks for primary fermentation but it is absolutely critical that primary fermentation is complete before you bottle your beers (do you bottle you beers?).

    As I mentioned previously, in all probability your fermentation is complete after 2 weeks of primary.

    Now, some people (as you have seen in this thread) like to conduct an ‘extended’ primary fermentation. The ‘extra’ 1-2 weeks provides additional bulk conditioning time to ‘mature’ the beer.

    What happens when you bottle your batch after two weeks of primary fermentation? Well, you are then entering a genuine secondary fermentation process. Transferring your beer from a primary to a carboy is referred to as a secondary but it is not a secondary fermentation process; it is just a conditioning process. As you discussed this step is not necessary.

    So, back to the bottling/secondary fermentation process. Once you bottle your beers two things are simultaneously occurring:

    · The secondary fermentation process whereby the yeast is ‘processing’ the priming sugar. The result is carbonation.

    · Additional conditioning of the beer; the beer will continue to ‘mature’ in the bottle.

    Even after carbonation is achieved (e.g., two weeks) the beer will continue to condition/mature in the bottle.

    As a homebrewer you get to decide how you want to ‘manage’ the conditioning process. You can conduct an ‘extended’ primary whereby you obtain some bulk conditioning after the primary fermentation is complete. You can also bottle your beers once primary fermentation is complete and condition your beer within the bottle. Your choice.

  10. GabeQ

    GabeQ Aficionado (160) Tennessee Feb 13, 2013

    Old thread but just wondering why you wouldn't re-hydrate the yeast?
  11. VikeMan

    VikeMan Champion (930) Pennsylvania Jul 12, 2009 Verified

    Laziness and/or the belief (true of not) that 1/2 of the cells will do as good a job as all of the cells. Lots of people say the don't rehydrate and make 'great' beers. YMMV.
    GabeQ likes this.
  12. Plakerio

    Plakerio Disciple (60) Virginia Jan 13, 2015

    My first brew is sitting in primary for a week. I'm absolutely new to this hobby. that said I followed the instructions to a T. when the recipe said DO NOT RE-HYDRATE and yeast told me to do so, I was at a loss. I think now after waiting 24 hours till vigorous sings of fermentation maybe I should have re-hydrate my yeast. Questioning why I would not re-hydrate?

    I'm treating my fist brew almost like my first baby. Funny having a grown man checking on beer every couple of hours (when i'm home). its scary When I already want 3 more beers going. This hobby seems to be getting the best of me.
  13. “Questioning why I would not re-hydrate?”

    By not re-hydrating you will ‘kill’ a portion of the yeast cells that you pitch into your wort (beer). It has been reported that up to 50% of yeast cells die if you don’t re-hydrate.

    "yeast told me to do so" Maybe because the yeast want to live!?!:confused:

    Plakerio likes this.
  14. Plakerio

    Plakerio Disciple (60) Virginia Jan 13, 2015

    the yeast control everything!
  15. Crazy as it sounds some yeast manufacturers do not recommend rehydrating their yeasts but instead just pitching directly into the wort. Not sure why that is, but some of them recommend doing it that way. Most of the dry yeasts that I use recommend rehydrating though, which I strongly agree with and always do unless the yeast manufacturer recommends against it. I always follow the directions that are printed on the particular packet of yeast that I will be pitching for that particular batch. You can also get a bunch of information by visiting the yeast manufacturers website - assuming they have one :)

    Also, what is interesting is that some yeast manufacturers state you can use either wort or sterilized water to rehydrate with, but the guidance for the Danstar Nottingham yeast explicity tells you not to use wort when rehydrating. http://www.danstaryeast.com/system/files/pdfs/nottingham_datasheet_0.pdf?download=1 - So the rule I follow is just start out with what the manufacturer of the yeast recommends and I think you find that will most likely work the best for you. Of course, there are always exceptions to every rule, but I have had good results sticking to what the yeast manufacturer recommends.

    Check out section "4" of the datasheet listed in the URL above. It has some good guidance on temperature and how it can shock yeast. I store my yeast in the fridge, and on brew day one of the first things I do is take the packet of yeast out of the fridge that I will be using and let it sit out until about an hour before I expect I'll be ready to pitch it. That way it can come to room temperature. I then take it and pitch it into sterilized water that has cooled down to the temperature of the room. This way the yeast and rehydration water is at the same temperature. Then chill your wort to the same temp as your rehydration water and pitch away. I've always (knock on wood) had good results with taking this approach and this is what I do unless the instructions on the yeast packet indicate otherwise.

    How did your first brew turn out?
  16. Can you please name the yeast manufacturers that specifically recommend that you do not rehydrate their yeasts.

  17. corbmoster

    corbmoster Savant (285) Texas Dec 15, 2014 Verified

    So, just to be clear, 3-4 weeks primary fermentation in a brew bucket in a keezer maintained environment would be perfectly fine? I have a scotch ale sitting shiny for almost 2 weeks. There is a possibility I might not be able to get CO2 to keg it for another week.
  18. JrGtr

    JrGtr Savant (450) Massachusetts Apr 13, 2006 Verified

    Perfectly fine. No problems at all. (presuming all else is fine.)
    pweis909 likes this.
  19. Hi Jack - it wasn't that they told you explicitly 'not' to rehydrate, they just didn't indicate it at all on their packaging. However, what is interesting is if you checked their website they basically say you don't 'have' to but you get better beer if you do. So I always rehydrated it as it is quite apparent that yeast works better when it is rehydrated. At least all of the yeast I've used does. It was a Mangrove Jack variety, can't remember which exact one though - but it did stand out as I thought it was odd they didn't say anything at all about rehydrating on their packaging. They just said pitch directly into the wort. I guess in their defense though, they are probably making it easier / more convenient for the new brewer. The yeast works great too. No problems with it at all and imparts a good flavor to my English brown ales.
    JackHorzempa likes this.
  20. VikeMan

    VikeMan Champion (930) Pennsylvania Jul 12, 2009 Verified

    Most instructions from most yeast manufacturers are designed to do this, which is why their recommendations are less useful for non-newbies.
  21. “I guess in their defense though, they are probably making it easier / more convenient for the new brewer.” I think that is their primary motivation but I think it is also easier for them to simply state something like a “Pitching: Sprinkle into wort” on a small package.

    “…if you checked their website they basically say you don't 'have' to but you get better beer if you do.” The motivation for re-hydrating dry yeast is that you get more viable yeast for fermentation. It has been reported that if you just sprinkle dry yeast into wort that up to 50% of the yeast cells die. Some homebrewers report that even with the loss of yeast cells they still produce ‘good’ beer by not re-hydrating.

    I personally re-hydrate dry yeast since it is my personal preference to maximize the number of viable yeast cells for my wort.

  22. Lukass

    Lukass Advocate (710) Ohio Dec 16, 2012 Verified

    The best stout I ever made I let sit in primary for 4 (almost 5) weeks cuz I was on vacation. Racked it right from there to the bottling bucket and it was delish! You'll be fine, in my experience, it gives the yeast time to clean up