Fermentation FAQ

Questions :

• Why isn't my beer fermenting yet?
• When are you supposed to rack (transfer) from the primary to the secondary?
• How long is too long in the secondary?
• What can I do about infected beer?
• What's the right temperature for fermentation?
• What can I do about a stalled beer (stuck fermentation)?
• Do I need to wait for these little bubbles to completely stop before bottling?

Answers :

• Why isn't my beer fermenting yet?
  > I pitched my yeast last night at about 7 o'clock, but when I looked
  > this morning I didn't see anything happening yet. Did I do something
  > wrong?
  
  This isn't enough information to diagnose your exact problem, but at least let me give you some of the more common things which could be going on here.
  
  The most likely scenario is that your beer is indeed fermenting very well at the moment, but the level of CO2 has not yet reached the saturation point, which means it all stays in the beer, which in turn means that your beer doesn't look like it's fermenting. Carefully give your fermenter a good stern shake to see if it suddenly foams up. Chances are it will, in which case we've confirmed the above.
  
  If you were using dry yeast, you can make your beer start fermenting faster by using two packages of yeast instead of one (which I do all the time), and also by making sure to rehydrate your yeast before using it. Good wort aeration is also important here. If it was liquid yeast you were using, then make sure you pitch a good healthy and large starter. And proper aeration is far more important with liquid yeast than it is with dry. See our yeast page for details on both of these.
  
  There is also a small chance that your beers has already completed fermenting. In 12 hours that's unlikely, but in 24 hours it certainly isn't unheard of. In fact, the Cooper's in the gold foil which I so faithfully use regularly finishes fermenting within 24 to 30 hours of having been pitched. Carefully shake the fermenter to see if you can raise a fizz. If so, then maybe it's already done.
  
  Yet another possibility is that you pitched the yeast when the wort was too hot, and thus killed the yeast. Make sure you have a reliable thermometer (the floating ones common in homebrew shops aren't reliable), and make sure you stir the wort well to mix properly. Above 100F/40C is not healthy for your yeast.
  
  
• When are you supposed to rack (transfer) from the primary to the secondary?
  > 1) In general, when should you rack to the secondary fermenter?
  
  Ideally immediately after the Kräusen settles. But you can leave it as long as 2 weeks (from beginning of primary) without worrying about any possible flavours resulting in the beer. Ales can be left long than Lagers. I've sometimes left Ales for more than a month with no problems.
  
  > 2) Should I wait until the krausen has completely dissolved or should
  > go ahead and rack to the secondary after the 6 days of primary
  > fermentation?
  
  As long as it is beginning to settle, you can rack. Most of what I've read (especially Noonan, if I recall correctly) says that there is a chance that racking can cause a stuck fermentation if you do it too long after High Kräusen settles down. I've never experienced this personally even though I've done that quite a lot, but it's useful to know just in case you do get bitten.
  
  > 3) Since one of the reasons for secondary fermentation is a clearer
  > beer, should I even be doing secondary fermentation on a Hefeweizen?
  
  Hefeweizen should be relatively clear, too. The wheat will give you sufficient haziness, as will the sediment from the bottle.
  
  
• How long is too long in the secondary?
• What can I do about infected beer?
  > Is one month at room temp too long for beer to sit in a carboy
  > secondary? It has one small (1/4 inch) colony of some kind of
  > comtamination but thats all. I meant to keg earlier but my 'promised'
  > keg never arrived from the Soda Keg Fairy. Damn Fairies. Can it be
  > saved?
  
  One month is not at all long for secondary. It's perhaps average. Mine generally sit at least a month in the secondary at room temperature.
  
  The first thing I always do with an infected beer, wine or mead is to pasteurize it to halt the infection from getting even worse. Slowly bring it up to 165F-170F, hold for 10 minutes or so, then chill, package, and reintroduce some fresh yeast (preferably a small starter of active yeast, but I've also used just rehydrated dry)
  
  If the taste is OK at this point, nothing more is required. In your case, the only thing I can recommend from experience is dry hopping. Just go out and pick up an ounce of 3-6% AA whole finishing hops appropriate to the beer style. If using pellets, add in a hop bag and put a copper pot scrubber over the bottom of the long dip tube. I'm not sure if pellet hops do as well for dry hopping, since I've only ever used whole hops for that.
  
  p.s. You sure that's an infection? The film kind? Or mold? Personally, whenever I get something like that, I pasteurize the beer and then reintroduce some yeast. I've only once had a beer ruined on me by an infection. The flavour was quite noticably off. But I just dry-hopped the hell out of it, and you could hardly tell the difference when drinking it ;-)
  
  
  cheers,
  -Alan
  
  
• What's the right temperature for fermentation?
  > A friend who homebrews told me that 60 was a very poor temperature for
  > fermentation, too cold for ale yeasts and not cold enough for lagering.
  
  Um, I'd kill for a consistent 60F. Most ale yeasts will perform just fine atthat temp (though you will find some that won't), and you'll get a much cleaner beer as a result. If your friend tells you to use some sort of heat-belt or something, you might want to consider finding a new source of advice. :-). You see, the higher temperatures cause the yeast to produce a lot more by-products, which all add their own flavours to the beer. So to some degree, it's a matter for your own taste buds. Some folks like their ales to have this extra flavour, some don't (though ales by definition should have some of this flavour). The key is that each yeast has a temperature or range of temperatures that it likes best. Many of these temperature ranges are well documented (for example on our yeast page). For many dry yeasts, though, it may require some trial and error on your part. We've found that both Munton's Gold and Cooper's in the gold foil perform very well in the 60F to 70F range.
  
  > I've decided to just go ahead and start anyway, and it *appears* to me
  > that fermentation has been going OK. I recently racked the beer into the
  > secondary and the SG was on target for the kit I'm making.
  
  See? Told ya :-)
  
  > So I was wondering, am I likely to experience problems brewing under
  > these conditions? Or should I be using certain yeasts that are better
  > under these lower temperatures?
  
  As I mentioned, you're gonna make better beer at 60F, IMO. At least better for my tastebuds. There are some ales where you do want a lot of fermentation by-products like those produced at higher temperatures, but in general I think most of us would prefer a constant 60F to a constant 70F, for example. Though that entire range should be considered acceptable.
  
  cheers,
  -Alan
  
  
• What can I do about a stalled beer (stuck fermentation)?
  
  Ah yes, the eternal question ...
  
  What's the hydrometer say now? If it is below 1.020 then I'd just live with it. If not, there are several things you can try, but they don't always work.
  
  - (1) Give the fermenter a good shake or stir to rouse the yeast
  - (2) Aerate again to wake up the yeast (could have bad side effects)
  - (3) Add some more wort to wake the yeast
  - (4) Add 1 to 2 litres of actively fermenting beer (high kraeusen)
  - (5) Add yeast nutrient and energizer according to instructions
  - (6) Move fermenter to a warmer place (only if it's too cold)
  - (7) pray
  
  The one most likely to work is the 5th - adding yeast nutrient and energizer. And if the cause is simply that the temperature dropped sharply, this could have shocked the yeast into going dormant. In this case get the temp back up to the proper range for your yeast (65F-70F for most Ale yeasts) and then stir to rouse the yeast back into suspension. But as I've said, if it is below 1.020 then live with it. In any case, this is a likely sign that you've done something wrong, so you should correct it for next time.
  
  Possible things that went wrong are :
  
  - mashed at too high a temp (all-grainers only)
  (not necessarily wrong, but will mean your fermentation will finish a lot quicker, so maybe what you are seeing now is
  simply expected. Is your thermomenter really accurate?)
  - didn't aerate well enough
  - didn't pitch enough yeast (not a big enough starter)
  - racked to 2ndary too late (very likely)
  - to much sugar or adjunct causing too little malt nutrients for yeast
  - ambient temperature of fermenter dropped sharply
  
  Something I've been reading about in Noonan's new book is Kraeusening your beer to help prevent it from sticking after racking. This involves taking off 2 before fermentation litres and storing it in the fridge before ferm, then adding it back (preferably actively fermenting) when you rack to 2ndary. I haven't tried this yet, but may try it on my next batch.
  
  To do this right you have to have good timing. 24 hours before you rack, draw off a pint or so of fermenting beer and add it to the 2 litres you drew off before to get it going (use an airlock and all the rest, of course), then dump that back in just after you rack.
  
  But chances are that there is some little thing you haven't done just right, and should correct next time around.
  
  
• Do I need to wait for these little bubbles to completely stop before bottling?
  
  No, you most certainly do not. This one strikes a humorous note with me, actually, because of my brother's first batch of beer (way back when I used to go to him for advise). The instructions clearly state to wait for all visible signs of fermentation to cease before bottling, and the little bubbles are indeed "visible signs". My brother's beer had to wait almost 6 months before he was convinced it was done.
  
  Realistically, that beer is going to be fermenting - albiet extremely slowly - for a long time to come, so don't take that "no visible signs" rule too literally. I generally just use a 1 week primary and a 2 week secondary, and almost without a single exception it's always done after that and ready to bottle/keg. The "no visible signs" means that the airlock is bubbling perhaps once per minute or less, and that all the really funky, messy, noisy stuff is over and done with. If you want to check to make sure, use your hydrometer. The exact final gravity will depend entirely upon your ingredients, but in general if it's below 1.015 then it's definitely ready to bottle/keg. For some beers (higher Original Gravity), that would be higher, for some beers it would be a bit lower. A general rule is that your gravity should be 1/3 or less of what it started out as. So if your OG was 1.045, then your FG should be 1.015 or lower. (1/3 of 45 is 15)
  
  The general rule is that most beers will have a final gravity that is 1/4 to 1/3 of the original gravity. So if you started off at 1.050, you can expectit will be done at 1.012 to 1.016 or so. The only exception would be if you were mashing and mashed at a very low temperature (149F-151F). See our mashing page for more details.
  
  If you suspect problems, check out our notes on stuck fermentation, or simply Email us.

Last Updated 2003.12.22 @ 09:23
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