Why leave in fermenter longer than final gravity?

[QldKev]

Keeping it in the kitchen might be a bit risky because the ambiant temperature would be well above 8C unless your an Eskimo.
My brewery is in my basement and doesnt get much above 10C most of the year. But then again I live in Tassy and we start to sweat when it gets above 16C down here....lol

16c, brrr a shiver just ran down my spine. I take it your talking overnight?

I shouldn't complain, it's only 23 in my office today. If it gets much colder I'll have to shut the windows

 

[chewy]

would you let settle for a few weeks then add finings ? these are probably dumbass questions but when we used to make HB i was a lot younger and it was all about getting it into the bottlethis time i really want to make some top quality beer...

 

[mash head]

Its also a good idea to rack the beer off the yeast cake once the primary fermentation is complete as the hungry yeast will start to eat themselves which can cause bad flavours. This is know as autolysis.
I rack my beer off after a few days of vigorous fermentation is over and then leave for a couple of weeks. I use honey in my brews and feel that the complex sugars need a bit of extra time to be gobbled up.

 

[Midnight Brew]

Its also a good idea to rack the beer off the yeast cake once the primary fermentation is complete as the hungry yeast will start to eat themselves which can cause bad flavours. This is know as autolysis.I rack my beer off after a few days of vigorous fermentation is over and then leave for a couple of weeks. I use honey in my brews and feel that the complex sugars need a bit of extra time to be gobbled up.

Really? Had a beer on the yeast cake for 4 weeks once when I went away and forgot about it. Had no such issue. In fact I've never heard of a home brewer who had autolysis problems. Not meaning to sound blunt but that sounds over the top.

 

[Charst]

Agree with midnight.


Comparing possible off flavours, racking to secondary and getting an infection is a far greater chance of off flavours then leaving the beer on a healthy yeast cake.
I regularly leave yeast on a cake for a month with no issues. I have two saisons sitting on a cake that are three weeks old now.

on the honey are you saying the honey's complex? because as far as i know honey if pretty much simple sugar and 100% fermentable

 

[sp0rk]

To quote John Palmer

"I should mention that by brewing with healthy yeast in a well-prepared wort, many experienced brewers, myself included, have been able to leave a beer in the primary fermenter for several months without any evidence of autolysis."

I have left an IPA on the yeast cake for 5 weeks and didn't detect any signs of autolysis

 

[wbosher]

I've gone three weeks quite often without any issues. From what I've read on most non-American sites, racking to secondary is becoming rare.

 

[mash head]

I learnt to brew from books, mainly Dave Millers. He seems to overstate the possibility of autolysis, after reading through, Papazian and Palmer they don't rate the issue as highly. I learnt to do things the way I do and will probably stick to it. Ive never had autolysis or an infection problem but doesn't mean it doesnt exist.
As for the honey, depending upon the flower variety around 80% of honey is sugars, the majority of these are 100% fermentable its the small percentage that aren't that Ive found benefits from time left in the fermenter. The issues Ive had in the past may not have had any thing to do with the small portion of complex carbohydrates found in the honey, but its my theory and I am sticking with it until proven different.

 

[pk.sax]

I think the practice to rack off after the vigorous fermentation is over might be linked to a commercial brewery wanting to free up the primary fermenters built to handle vigorous ferments and contain krausen etc for the next batch. Transfer off to the bright tanks and let it finish there. Doubt it does too much for a home brewer using the same kind of fermenters for both primary and secondary and not brewing with such regularity. Still, I think it'd be a great idea to use this method if storing fermented un-carbonated beer in non pressurised glass or the like for longer times, leave behind the more flocculant sleepy yeast. Bit of a blind scale reduction of a brewery's processes but there might a good point or two in it.

PS: before it's asked, yes, I have done that. Kept beer in carboys for a couple of months after taking off the yeast cake. Beer was beautiful. Motive was to transfer to containers that'd fit in my fridge rather than anything else.

 

[chewy]

If I could rack of the beer it would probably be easier and transfer it into the actual fridge which is bigger than my fermenter chamber and then I could begin another batch...!!!

 

[Byran]

I really find that racking to secondary is just a time saving solution for clearing the beer faster. If you leave it in primary you can get blobs of gunk in your kegs or in suspension which takes days or weeks to clear, but if racked onto gelatin into a secondary the beer will get off the main bulk of stuff in the primary and drop the solids out very quickly. Making clear, clean kegging very easy and fast. Only a couple of days. And you get nothing but clean beer in your kegs and bottles. I just done some ales , primary to keg but I like that they stay a bit cloudy. With lagers I will always secondary.

 

[mash head]

From Mr Palmers book How to brew page 90;
The dormant yeast on the bottom of the fermenter will excrete undesirable amino and fatty acids. Leaving the post-primary beer on the trub and yeast cake for too long (more than a month for example) can result in soapy flavours in the beer due to oxidation and other chemical reactions.
Note the word CAN.
The last paragraph of this section answers the OPs question.
Leaving an ale beer in the primary fermenter for a total of two or three weeks, instead of just one will provide time for the conditioning reactions and improve the beer. The extra time will also let more sediment settle out before bottling, resulting in a cleaner beer and easier pouring.

 

[chewy]

if i rack into a secondary do i have to purge the air out of it?

 

[Byran]

If you rack to secondary and still have some CO2 in the yeast trub and CO2 dissolved in the beer (which is often the case) the beer will release CO2 when transferring. Put the lid on, give it a light slosh around and crack the lid to let the gas purge itself, then tighten the lid. If no gas releases from the liquid you can purge it with CO2 from a bottle if you have one, then put the lid on. I've done it heaps of times and never had oxidation, yet.
I usually put the secondary straight into cold conditioning but if you intend to keep it at ferment temps ( to rouse it and drop the FG a little more) Id suggest transferring quite a bit of yeast trub into the secondary or you might stress the yeast and cause off flavours in your beer.