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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 (785) Pennsylvania Jul 12, 2009

    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 (785) Pennsylvania Jul 12, 2009

    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 (325) New Jersey Jun 10, 2008


    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 (785) Pennsylvania Jul 12, 2009

    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 Initiate (15) 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 Initiate (15) Virginia Jan 13, 2015

    the yeast control everything!

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