Racking & Stuck Ferments!

[BarneyG]

Hey Fella's,

I know this has been done heaps!

I've read heaps on Racking and Stuck Ferments, and below is what I've come up with B) There is tonnes of info on this subject, ie when is the best time, etc, etc .

Tell me whether or not I'm right, and what else I need to know I want to rack my beer in the next few days.

Racking:

1. Worts with an S.G. higher than 1.050 should be racked.

2. Racking should be done once half the OG has been reached,
ie O.G 1.050 - F.G. 1.010, racking should be done at 1.030.

3. When racking take some Krausen into the next fermenter.

Stuck Ferment's: (I hope this doesnt happen to me! again )

1. Gentle rock the fermenter to stir up the yeast.

2. Give the Wort a quick stir, to get some air into it.

3. If still no good, pitch yeast again.


All comments and suggestions welcome

 

[GMK]

Barney

I allways rack at 7 - 10 days...when i feel that primary fermentation has just about finished.

I dont perscribe to the racking at day 3 or half gravity - i feel that this promotes stuck ferments and can lead to oxidation problems.

Just my 2 cents worth.

 

[SJW]

I will be looking forward to these answers. I dont understand why you need to rack if your going to CC. I would not of thought that a couple of extra days on the yeast cake would hurt. I have never racked and all my beer's are pretty clear. Although i am doing a Pilsener at the moment and i am going to let it ferment out, and then cc for a couple of weeks. That should be fine.

 

[Hoops]

BarneyG

I do the same as GMK, rack after about 7-10days when the primary fermentation has slowed right down, then CC

 

[Wax]

BarneyG,

I also rack after 7ish days. I usually condition in seconday for a couple of weeks then keg. No probs so far.

 

[BarneyG]

Guys, I ordinarily rack at 7-10 days aswell , but with Worts that have a big O.G. some tend to have a high F.G. Hence the need for racking to get the wort down to respectable F.G. of about 1.010-1.008.

I've heard/read alot of people saying that when fermentation is complete with a high initial O.G., they tend to have a F.G. of about 1.020-1.016. I feel that even though there wort isn't bubbling, it doesn't necessarily means fermentation has completed. I put this down to not racking. <_<

Does this sound right? Or am'I just waffling. B)

 

[GMK]

Barney

I brew big beers - Scotish Ales Barley Wines, RIS etc.
Well over 1050 - usually 1075 -1100.

I will rack after 10-14 days with these, FG around 1016-1020 at 18 degrees.
Dry Hop and CC for 2-6 weeks.
Now then when i take a FG reading again at the end prior to bottling - it is around 1012-1016...but the wort temp is around 4 degrees.

I am happy with this. It means taht the yeasty beasties have left some stuff for me....and done a little bit more fermenting in the fridge.

Hope this helps.

 

[kook]

I've heard/read alot of people saying that when fermentation is complete with a high initial O.G., they tend to have a F.G. of about 1.020-1.016. I feel that even though there wort isn't bubbling, it doesn't necessarily means fermentation has completed. I put this down to not racking. <_<

Does this sound right? Or am'I just waffling. B)

Theres no way you'll get every beer down below a certain gravity. It depends entirely on the attenuation of the strain of yeast. Look up the specs for the yeast you're using. It'll be representated as percentage. You can then work out based on the original gravity what the estimated final gravity will be.

I normally rack when the beer is finished, the gravity doesnt drop anymore after this. Most of the yeast has flocculated, and any that is roused from movement during racking usually floccs out while it is in secondary.

 

[Wax]

I normally rack when the beer is finished, the gravity doesnt drop anymore after this. Most of the yeast has flocculated, and any that is roused from movement during racking usually floccs out while it is in secondary.

So Kook, if your racking after the yeasties have done their work how do you avoid oxidiation in the secondary?
Also, how long do you leave it in the secondary?

 

[BarneyG]

Theres no way you'll get every beer down below a certain gravity. It depends entirely on the attenuation of the strain of yeast. Look up the specs for the yeast you're using. It'll be representated as percentage. You can then work out based on the original gravity what the estimated final gravity will be.

I'm using wyeast 3944: apparent attenuation 72-76%. As per wyeast lab's web site.

My initial O.G. is 1.061, hence my F.G should be around: 1.011-1.009. Which sounds pretty good to me.

I normally rack when the beer is finished, the gravity doesnt drop anymore after this. Most of the yeast has flocculated, and any that is roused from movement during racking usually floccs out while it is in secondary.

I can't understand why rack when fermenting is complete :unsure: If fermenting is truly completed, you should be able to CC straight away from the primary me thinks?? :blink:

 

[deebee]

I reckon racking can actually trigger a stuck brew and don't do it until all obvious signs of fermentation have ceased. The point of racking at this stage is to take the brew off the yeast cake and allow me to condition it at room temp without risk of autolysis. You could always condition in the frig if you have the frig space for it.

Stuck ferments are bloody hard to kick off again. If it happens, I tend to just underprime and bottle, but I have had limited success with adding an active well-aerated starter, manually rousing the yeast and raising temperature. Can generally squeeze a couple more gravity points out of it.

 

[wedge]

i rack after 7 days into a secondary, just to rouse up the yeast and help the brew ferment out those final points.

I leave in the secondary letting the yeast to settle and the fermentation to finish.

I am usually left with a pretty presentable beer after this.

I then CC for a further 4 weeks (at least). I'm usually left with a clear beer then, plus a great tasting one, (usually).

 

[RobW]

My initial O.G. is 1.061, hence my F.G should be around: 1.011-1.009. Which sounds pretty good to me.



I can't understand why rack when fermenting is complete :unsure: If fermenting is truly completed, you should be able to CC straight away from the primary me thinks??

I think you'd get closer to 1015-17 FG with that attenuation.

The reason I rack at the end of fermentation is to get the beer off the yeast so it goes into secondary nice & clean. More drops out over the next week or so & then the cc polishes it up nicely at the end.

 

[Wax]

Wedge,

Do you CC in the keg? Or do you CC in secondary?

 

[Hopeye]

I just racked a lager after 14 days and the SG was 1.030 (seemd to be stuck to me), and it is now bubbling more than the stout that I put down on the weekend. So, from this I gather that if you've got a stuck ferment because you've either shocked the yeast (by dropping the temp too quickly) or poor areation, racking can help.

Just my 2 cents.

 

[Hoops]

OK I ferment in my fridge until signs of fermentation has ceased or slowed right down.
I then rack into a secondary to get off the yeast to avoid autolysis. The secondary I use is a big glass carboy which means there is very little surface area to avoid oxidation.
This is then CC'd for anywhere from 1 week to 2 months (depends how much stock I have left). This settles nearly all the yeast from suspension and clears the beer right up.
I then transfer to a keg and it stays in my keg fridge.

Hoops

 

[kook]

So Kook, if your racking after the yeasties have done their work how do you avoid oxidiation in the secondary?
Also, how long do you leave it in the secondary?

Theres not much headspace (less than 5 litres) left in my cube or my 25L fermenter (both of which I use for secondary). I've considered purging with CO2 but I dont think its really an issue. Theres a bit of dissolved CO2 in the beer anyway.

2 weeks normally.

 

[kook]

I'm using wyeast 3944: apparent attenuation 72-76%. As per wyeast lab's web site.

My initial O.G. is 1.061, hence my F.G should be around: 1.011-1.009. Which sounds pretty good to me.

I can't understand why rack when fermenting is complete :unsure: If fermenting is truly completed, you should be able to CC straight away from the primary me thinks?? :blink:

If the apparent attenuation is 72-76%, and your OG is 1.061, shouldnt your FG be 1.015-1.017 ? To get down to 1.009 from 1.061 wouldnt you be looking at 85% attenuation?

I only got a fridge recently, so before I used to rack so as to get the beer off the primary yeast cake. Temperatures in Perth tend to favour autolysis (so as I found with two brews last october). The other main reason I do it is clarity. I find that if I rack it from the primary fermenter into a secondary, the remaining yeast floccs out while its conditioning, and isnt stirred up when I rack it to a keg or bottling bucket. Beforehand I found that due to the size of the yeast cake, more of it was picked up while transferring the beer to keg/bottle.

 

[Jovial_Monk]

For big beers, remember aeration, before and 14-18 hours after pitching.

According to Dr Chris White of White Labs fame, leave the beer in the primary two weeks, the yeast cake is cleaning up the beer of diacetyl, etc. then rack off the yeast (and trub, hob debris, etc) into a cube and cold condition.

A fermentation should take no more than 5 days for ales, a bit longer for lagers, and generally finishes at about 1/4 of OG. At the end of fermentation the beer will be supersaturated with CO2, moving/shaking the fermenter or racking may get this CO2 to come out of solution and bubble out of the airlock--this is often mistaken for a new burst of fermentation!

A stuck ferment can sometimes be restarted by swirling the fermenter, or by carefully stirring the yeast sitting on the bottom back up into the beer with a sanitised brewpaddle. This is usually good enough to drop the gravity a few points only. I have a mead that dropped a hundred points, but needs to drop another 50-60, that will require rather more effort!

Working out the final gravity based on OG, fermentability of the grist and the attenuation power of the yeast is complex. Even a 100% attenuative yeast will only ferment 10% of an all roast barley wort.

As a rule of thumb, Fg will be about 1/4 of OG

"Homebrewing" by G Wheeler has more details about predicting final Gravity


Jovial Monk

 

[BarneyG]

Thanks for all the replies

Kook & Keneasy, my calculations were incorrect, your indications of 1.015-1.017, sounds more precise, I checked this out on the grumpys calculator.

http://www.grumpys.com.au/brew_analyser.php3

Look's like CC'ing for 1 month is pretty much standard. h34r: