The great fermentation debate!! Lol

Okay first time posting so excuse me because I'm sure this has been brought up it I couldn't find what I was looking for.
Why is everyone wanting to leave there beer on the yeast for so long? To me it doesn't make a shred of sense. Scientifically when fermentation is complete it is complete your beer is not going to get any more done. Now different strains of yeast work differently some taking a lot longer than others ect. But cmon some guys saying they leave the beer on a yeast cake for a month or longer??? Why!? Lol I also understand off-favors, hot,spicy anything but sour will clear up after bottling or batch aging but it doesn't need to be in the fermenter for that to happen. I used to use the 2 week rule and that has always worked well for me but now after talking to some bad ass Brewers my whole idea about fermentation has changed. Now with a great starter and practice I can obtain a OG 1.060+ cool,pitch and see fermentation start in less than 6 hours and be completely done in 3-4 days almost always hitting my FG ... Crash, Then bottle and or keg and let sit for a couple weeks then [emoji482].. So what I'm trying to get at is everyone crazy? Are these guys who brew for a living crazy? I don't know but I sure want to know where it started and why We're all here to better our beer so if I'm wrong tell me why so I can learn from ya! Thanks guys,, cheers!

You are definitely not the only brewer who does this. I won't speculate on all the reasons the pro leave it for a month crowd is so vocal. But they are. Fine with me. I just think people need to know it isn't necessary to make good beer. Keep brewing the way that makes you happy.

It's simply a matter of preference. We are under no compunction to do what commercial brewers do. I use a fermentation schedule that works for me based on my own experience. That's why it's called HOMEbrewing.

the only thing i would wanna know if someone is touting a new method is if these beers taste fine to them, or do they also taste off-flavorless to homebrew clubs, homebrew competition judges, etc. otherwise it's just some other joe schmo like myself who likely just hasn't honed in the ability to taste the off-flavors that likely shouldn't be in that "style."
that being said, i'm all for new, proven techniques that might come off as experimental and crazy at the outset. so long as they're coming from a reliable source and not somebody new to homebrewing (not saying the OP is).

I've kegged in as little as 8 days, if it's done, it's done. I've also let sit for a few months for some Belgians and RISs. Some of the more hoppy, roasty or high gravity beers benefit from a little aging, but they can do that in the keg.

Just do what you are happy with.

Yes I suppose so.. What ever works for us I guess.. I guess I'm just looking for more "scientifically just reasons"..I am a super nerd about brewing and I'm always looking for proven reasoning behind technique. If anyone has anything I would really like to know...

shawnbrews1 said:

Yes I suppose so.. What ever works for us I guess.. I guess I'm just looking for more "scientifically just reasons"..I am a super nerd about brewing and I'm always looking for proven reasoning behind technique. If anyone has anything I would really like to know...

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Sure some off-flavors can clear out in the bottle, but I'd guess that being in contact with larger quantities of yeast (i.e. the yeast cake vs what is in a bottle) will clear up those off-flavors faster. In which case it makes more sense to keep on the cake for a little while.

Something can be said for bulk aging as well. Many contend that their beer tastes better (or at least ages more uniformly) when done in bulk than when done in the bottle.

Furthermore, no harm no foul. It's not hurting anything and if you're not in a hurry it can sit there safely. Not everything is done with the intent of optimization and maximum efficiency. So RDWHAHB.

I leave mine on the yeast cake for 4 or 5 weeks almost every time. My extremely scientific reason for doing so is that I'm busy, bottling is time-consuming, we have no room for kegging, and I already have beer in my refrigerator.

I would also think the pros literally have it down to a science and know what flavor they want and can expect from a beer after a given length of fermentation and are happy with what they get out of a "shorter" time on the yeast. I bet Sierra Nevada Pale Ale would taste different if it was left on the yeast longer but since they are under the gun to produce the same tasting beer batch after batch, we'll never know. And even if it's only on the yeast for 3 days, it tastes damn good

Pros rush because tied up fermenters cost money.

I used to be in the "leave it for four weeks" crowd. And I think most new brewers would be best served by following that. And as mentioned above, during the stationary phase of fermentation while intermediaries are being reabsorbed, the beer needs to be on the yeast. I don't recall exactly why that is, and I don't care to go get the book off the shelf. But if all the fermentation parameters are healthy (proper pitch of yeast, proper dissolved oxygen, good temp control, proper yeast nutrition, etc) that stationary cleanup is over very rapidly.

So the point is, once you reach FG doesn't mean you're done. It's once those intermediary compounds are reabsorbed (or at least as reabsorbed as they're going to get) that it's done. When you aren't getting an ideal fermentation (not pitching enough yeast, poor temp control, not properly oxygenating, etc), then greater intermediaries and result, and it can take longer to reduce them to acceptable levels (or they may never reduce low enough at all).

I guess what I'm trying to say, the better a brewer you are (or rather, the better an environment you give your yeast) the faster you will be done. My beers generally hit FG 3-7 days after pitching yeast, and will usually be fully conditioned a day or two after that, ie total of 4 or 5 days in some cases (like an English style session beer). I usually package around the 14 day mark, but I've gone less., and if I can't get to it in time, I have no problems associated with 4-5 weeks fermenter time.

shawnbrews1 said:

Why is everyone wanting to leave there beer on the yeast for so long? To me it doesn't make a shred of sense. Scientifically when fermentation is complete it is complete your beer is not going to get any more done.

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There are lots of answers to your question, and unfortunately, there is not a one-size-fits-all answer. Some beers need to be aged. Others need a diacetyl rest. Lagers need to be lagered. Just because fermentation is "complete" doesn't mean the beer is at its optimal flavor.

There used to be a concern about autolysis from having the beer sitting on the cake too long. That has long since been debunked--at least at the homebrewing level. (In large conical fermentors used by commercial brewers there is a risk of autolysis, due to the greater pressures involved.)

Yes I totally agree. A lot of beers need to be aged,lagered ect. But all of these practices are always done off the yeast. Aging beer is almost always done in keg or bottle,barrel. So yes I agree not a one size fits all but the question remains... Why keep on the yeast??

Are you trolling?

All good points . I know there is no rush to remove from primary and I'm not arguing that there is. I was only looking for a reason that almost everyone in these homebrew forums say that it MUST REMAIN IN PRIMARY. . And saying that with absolutely no reasoning behind it except, "I'm not in a rush" well neither am I. Just wanted to know if any experienced Brewers could school me.

flars said:

Are you trolling?

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What??

I've always wondered about the whole "leaving it on the yeasts helps clear up any potential off-flavors." Is there any metric here? We all know aging can help reduce some undesirable flavors as well as let everything meld together a bit, but I wonder if there's any true science backing to that. Is the dormant trub really scrubbing phenols or is it something else?

But as for the topic - a few weeks is just a safe bet to tell noobies so they don't bottle too soon etc. Anyone saying IT MUST REMAIN is being overbearing.

The main reason for leaving the beer on the cake is reduction of acetaldehyde and diacetyl. The mellowing parts can be done in the bottle. But again, a properly done fermentation this can take a day or two, not weeks. If the quality of fermentation was poor, then it can take longer. But if you remove from the yeast, they will not reduce properly. And I taste plenty of beer I judge in competition with acetaldehyde (my sensitivity to diacetyl is low, but there's definitely some of that too- and if I can easily taste it then it's bloody extreme to others). Probably from brewers rushing, cold crashing and kegging before the beer was ready. If the beer is done, it's done. But if you're cold crashing the day you reach FG you're rushing. Just because you can't necessarily taste it doesn't mean it's not there.

The main reason I leave it on the cake is to limit exposure. Be it to oxygen or possible contaminants during transfer. But that's somewhat secondary to letting the yeast finish their jobs. It seems there is no real reason NOT to let the beer sit on its cake. Especially when, as stated above, while final gravity may have been reached, there are still benefits to be had from leaving it on.

Awesome!!! Finally somebody actually has a reason! Haha. Thank you for the info. So to play it safe I think I'll wait until FG +1 week.. Thank you

I leave most of my beers in primary for 2 weeks. fermentation is generally done in 3-5 days but it doesnt hurt to let it set for another week for cleanup and settling. I really have not see much talk of leaving it longer than 2 weeks.

I will try to be scientific here... (or not) not everyone has the same ability to taste the "off" flavors generated in some home brews. A long time ago I brewed a beer that had the diacetyl "butter" flavor, and I was the only person that didn't taste it. My temperatures were not tightly controlled back then. OP, 6 hours to start and 3-4 days to finish, how are you controlling your fermentation temperatures? Are you able to keep the center of your fermenter plus or minus 3 degrees? Although the pros have all kinds of hardware and equipment to tightly control their process, it is much less costly in the long term for them to play it safe rather than sorry when it comes to (not) hurrying a batch of beer. ESB 1968 is a very versatile yeast; (for example) the brewery is making a style of ale that has a fruity character to it, but by pushing the fruit character during fermentation there is a great chance of undesirable flavors, especially diacetyl. By leaving the ale on the yeast any undesirables that may have occurred during fermentation are removed by the yeast.

EDIT: I wrote this post before post #7 was up, so forgive me for taking two hours to post this message.

MindenMan said:

I will try to be scientific here... (or not) not everyone has the same ability to taste the "off" flavors generated in some home brews. A long time ago I brewed a beer that had the diacetyl "butter" flavor, and I was the only person that didn't taste it. My temperatures were not tightly controlled back then. OP, 6 hours to start and 3-4 days to finish, how are you controlling your fermentation temperatures? Are you able to keep the center of your fermenter plus or minus 3 degrees? Although the pros have all kinds of hardware and equipment to tightly control their process, it is much less costly in the long term for them to play it safe rather than sorry when it comes to (not) hurrying a batch of beer. ESB 1968 is a very versatile yeast; (for example) the brewery is making a style of ale that has a fruity character to it, but by pushing the fruit character during fermentation there is a great chance of undesirable flavors, especially diacetyl. By leaving the ale on the yeast any undesirables that may have occurred during fermentation are removed by the yeast.

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Yes I use a large ferm chamber that is temp controlled and for almost all ales is set at 66f and sometimes a little higher for the first 24 hours. And you are right with certain types of yeast that work slower and at higher temps there is a greater chance of there being off-favors and usually with a higher abv. That is why aging is almost always recommended to let the hot and spicy alcoholic flavors to mellow out. But also can be done off the cake. There will always be a sufficient amount of yeast still in suspension at the homebrew level to do the job of mellowing out the brew .

MindenMan said:

I will try to be scientific here... (or not) not everyone has the same ability to taste the "off" flavors generated in some home brews. A long time ago I brewed a beer that had the diacetyl "butter" flavor, and I was the only person that didn't taste it. My temperatures were not tightly controlled back then. OP, 6 hours to start and 3-4 days to finish, how are you controlling your fermentation temperatures? Are you able to keep the center of your fermenter plus or minus 3 degrees? Although the pros have all kinds of hardware and equipment to tightly control their process, it is much less costly in the long term for them to play it safe rather than sorry when it comes to (not) hurrying a batch of beer. ESB 1968 is a very versatile yeast; (for example) the brewery is making a style of ale that has a fruity character to it, but by pushing the fruit character during fermentation there is a great chance of undesirable flavors, especially diacetyl. By leaving the ale on the yeast any undesirables that may have occurred during fermentation are removed by the yeast.

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Yes I use a large ferm chamber that is temp controlled and for almost all ales is set at 66f and sometimes a little higher for the first 24 hours. And you are right with certain types of yeast that work slower and at higher temps there is a greater chance of there being off-favors and usually with a higher abv. That is why aging is almost always recommended to let the hot and spicy alcoholic flavors to mellow out. But also can be done off the cake. There will always be a sufficient amount of yeast still in suspension at the homebrew level to do the job of mellowing out the brew .

The time my beer sits on the yeast has more to do with my pipeline than anything else. 4-6 weeks is fairly common for me as I try to stay two beers ahead of what's on tap.
I can taste the difference between a 2 wk beer on tap verses a 6 week beer.
Just my personal preference, but I almost always prefer the more "aged" beer

Cheers

They may have changed their minds but either Ray Daniels in Designing Great Beer or Gordon Strong in Brewing Better Beer wrote that they think that letting beer sit on a yeast cake for > a month begins to run the risk of off flavors due to yeast autolysis.

I typically give it 2 weeks on the yeast cake before cold crashing and bottling.


Not letting it sit 6+ weeks on the yeast cake is not the same as racking to a secondary to clear the beer.
If I plan on aging a beer, I rack to an oxygen resistant Better Bottle after a couple of weeks.

depending on the beer im making, Ive kegged by day 9 for cream ales, pale ales, golden ales. Other beers such as Imperial chocolate milk stout, Ive waited up to 2 weeks in the primary, and 3 weeks in the secondary before moving on to kegs.

Higher gravity beers need more time but your perfectly okay moving most low complexity ales. When fermentation is over, all that matters is how clear you want your beer.

letting beer sit on a yeast cake for > a month begins to run the risk of off flavors due to yeast autolysis.

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Exactly, Ive read this too. Which is why I move the beer at a max at the 3 week mark. If I have something really heavy or the yeast are not attenuating well, I would move the beer still by 3 weeks and continue fermentation in another vessel.

Ive had yeasty beer. Its aweful.

Balloonknot said:

depending on the beer im making, Ive kegged by day 9 for cream ales, pale ales, golden ales. Other beers such as Imperial chocolate milk stout, Ive waited up to 2 weeks in the primary, and 3 weeks in the secondary before moving on to kegs.

Higher gravity beers need more time but your perfectly okay moving most low complexity ales. When fermentation is over, all that matters is how clear you want your beer.


Exactly, Ive read this too. Which is why I move the beer at a max at the 3 week mark. If I have something really heavy or the yeast are not attenuating well, I would move the beer still by 3 weeks and continue fermentation in another vessel.

Ive had yeasty beer. Its aweful.

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Makes a lot of sense.. Thanks man!

Balloonknot said:

depending on the beer im making, Ive kegged by day 9 for cream ales, pale ales, golden ales. Other beers such as Imperial chocolate milk stout, Ive waited up to 2 weeks in the primary, and 3 weeks in the secondary before moving on to kegs.

Higher gravity beers need more time but your perfectly okay moving most low complexity ales. When fermentation is over, all that matters is how clear you want your beer.


Exactly, Ive read this too. Which is why I move the beer at a max at the 3 week mark. If I have something really heavy or the yeast are not attenuating well, I would move the beer still by 3 weeks and continue fermentation in another vessel.

Ive had yeasty beer. Its aweful.

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Makes a lot of sense... Thanks man!

shawnbrews1 said:

I'm just looking for more "scientifically just reasons"..I am a super nerd about brewing

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Gary_Oak is back? Have you read books?

being serious now,

Dr. Yeast, Chris White, founder of White Labs wrote the Life Cycle of Yeast


might help you with the scientific side of things. looks like after 10 days, under ideal conditions (proper pitch, yeast health and all that), most normal-sized beers are ready within 10 days, but there is no down side to letting it sit on the yeast for an additional length of time, within reason & limits of your equipment

this is one of the aforementioned types of people i would take guidance from in a discussion like this.
http://brulosophy.com/2015/06/25/pitch-ramp-crash-how-i-ferment/

i think the biggest thing to take away from it isn't the timeline (although that's certainly the next biggest thing), but rather the parameters of being able to make such a claim. you need to be pitching sufficient (maybe even more than just sufficient), healthy yeast in a normal sized beer which is fermented in a temperature controlled environment. If you don't have those three things down to go along with your normal sized beer, it's likely you're not going to get the timeline down. the same factors discussed in the above post.

those are such important factors it's probably often why people don't give such advice to the new brewers. most of us would get so excited about being able to drink the beer sooner, we'd likely skip over that whole condition-of-the-yeast part.

GrogNerd said:

Gary_Oak is back? Have you read books?

being serious now,

Dr. Yeast, Chris White, founder of White Labs wrote the Life Cycle of Yeast


might help you with the scientific side of things. looks like after 10 days, under ideal conditions (proper pitch, yeast health and all that), most normal-sized beers are ready within 10 days, but there is no down side to letting it sit on the yeast for an additional length of time, within reason & limits of your equipment

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Came for the Gary_Oak reference. Leaving satisfied.

Something should be said for bulk aging:

A month in the primary gives that beer that much more time to age. Then when you start drinking after carbonation it already has that age instead of still being a little young.

Either way I'm not too concerned with time in primary whether it is a month or two weeks. I'll usually give my bigger beers more time. Beers that are better young may only get a couple weeks.

I just had a bitter in the primary for almost a month while finishing my kegerator. After carbing one week it basically tasted like it did at the end of bottling the last time I made it. That time I only did two weeks in the primary.

So for me bulk aging is a good reason to primary longer.

shawnbrews1 said:

All good points . I know there is no rush to remove from primary and I'm not arguing that there is. I was only looking for a reason that almost everyone in these homebrew forums say that it MUST REMAIN IN PRIMARY. . And saying that with absolutely no reasoning behind it except, "I'm not in a rush" well neither am I. Just wanted to know if any experienced Brewers could school me.

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One thing that I recommend is to try it yourself. Split a batch in half, and leave half in the fermenter for as long as it takes to reach FG, and then add three days for this "clean up" phase talked about. (In reality, that 'clean up phase' is over within 24 hours after the beer reaching FG, generally). But a couple of extra days for the beer to clear a bit is a good thing. Once it's clear (or clearing), package the beer. Then, leave the other batch for 4 weeks. Keep all things the same- same amount of yeast pitched at the same temperature, and fermented at the same temperature.

They will be different. See which YOU prefer.

My preference is the former; but some prefer the latter.

Basic Brewing Radio had a podcast on this experiment a couple of years ago. The interesting thing was that tasters were about evenly split on their preferences, so some liked the beer with less yeast character imparted by the shorter time in the fermenter, while just as many seemed to prefer the beer out of the lengthy primary.

I really don't think it's at all a majority of brewers who do ultra-long primaries, but they certainly are the most vocal of the folks who advocate one or the other.

That's a great idea and exactly what I will do on the next one! Thank you