51 replies to this topic

[CaptRon]

Sooo, I know nothing about this subject, what it is, or what it means. Matter of fact I didn't know the word existed until it came up in the 'Green Board' thread. But all of the talk about it has me curious as to what it is.So, lets see what you got. Mtn

[ChicagoWaterGuy]

Sooo, I know nothing about this subject, what it is, or what it means. Matter of fact I didn't know the word existed until it came up in the 'Green Board' thread. But all of the talk about it has me curious as to what it is.So, lets see what you got. Mtn

Basically, yeast cells rupture and their guts spill out into your beer. Now your beer tastes like vegemite. Which may be cool if you're an Aussie, but sucks for the rest of the world.

[MtnBrewer]

LOLOk, here's what I know about it, which really isn't all that much. Autolysis is what happens when yeast run out of something to eat and so they eat each other. That's an oversimplification but I think it gets the point across. The yeast are trying to survive and so they try to consume anything they can.The reason it's important is that autolysis produces some really horrible off-flavors. I've heard "rubbery" used as a descriptor for autolysis and I guess it's as good as anything but doesn't really convey the nastiness that is autolysis. Next time you transfer a batch out of primary when you don't plan to reuse the yeast, save the slurry in a mason jar. Cover it with foil or something and leave it out for a couple of months. Then open it up and experience the full glory of autolysis.Fortunately, autolysis is not as easy to produce as was once thought. When I first got into homebrewing (during the Coolidge administration) it was thought that if you left your beer in primary for more than 2-3 weeks, autolysis would set in and ruin the batch. So everybody got super duper paranoid about it (sort of like sanitation these days). Turns out that it takes much longer for it to set in than everybody thought. Instead of a matter of a few weeks, the actual time is on the order of a few months. Maybe as little as 6-8 weeks but I've had a beer in primary for a couple of months and had no problems with it.Ironically, autolysis is responsible for some beneficial flavor components in wine and mead. I don't know why that is. Perhaps due to the different yeasts used. That's about all I can think of so I'll open it up for discussion.

[CaptRon]

Interesting...So is that where the idea of transferring to a secondary initially came from? To get it off that yeast cake before it starts happening? I can see that, and then the additional clarifying is another benefit.Honestly, I'm not too sold on the secondary aspect either anymore as I skip secondary altogether nowadays and go right in to keg after primary. Unless I'm going to be reusing the yeast cake then I might move to secodary.

[MtnBrewer]

Interesting...So is that where the idea of transferring to a secondary initially came from? To get it off that yeast cake before it starts happening? I can see that, and then the additional clarifying is another benefit.

That was one reason for sure. The first home brew book I ever latched onto was Dave Miller's Complete Handbook. In it, he drove home the point that ZOMG YOU MUST RACK THE BEER BEFORE AUTOLYSIS SETS IN!! I have to say that it's about the only thing I've ever known of Dave to be wrong about. [And to be fair, he's not really wrong per se, just a little overcautious.]

Honestly, I'm not too sold on the secondary aspect either anymore as I skip secondary altogether nowadays and go right in to keg after primary. Unless I'm going to be reusing the yeast cake then I might move to secondary.

Yeah, I think a lot of brewers (me included) feel that way. If I'm just doing a "normal" beer that I'm going to keg, I frequently won't bother with secondary. I'll just do a longer primary and then go straight to keg.

[SchwanzBrewer]

Yeah, I think a lot of brewers (me included) feel that way. If I'm just doing a "normal" beer that I'm going to keg, I frequently won't bother with secondary. I'll just do a longer primary and then go straight to keg.

I hate racking, so I do primary for 2 weeks, 1 week in the fridge (still in primary), 1 week keg on CO2 for carb now that I have my kegging system.2 or 3 beers ago I left the beer in primary for 6 weeks (in the swamp cooler) and I didn't smell anything bad or get off flavors that I could tell. So i would say it takes some time and a little effort to get autolysis. I think if you disturb the beer and raise the temp you would probably get it a lot easier.Cheers,Rich

[djinkc]

I don't think it's a very common occurence. And that's my understanding also that the yeast starts to cannabilize itself. I've had it happen once with my brews. Meaty is a good description for what I had, maybe a little burnt rubber too. Absolutely disgusting and undrinkable. I don't really remember what abuse I put the beer through to get it - this was in the early 80's - but the taste and smell are unfortunately unforgetable. I've never run across it again, except at some fast food franchise - I forget

[ThroatwobblerMangrove]

Temperature has to be a big factor. I keep yeast samples around in the fridge for 6-7 months without doing anything with them sometimes and they've been fine. Also - consider bottles with yeast sediment in them - seem to be fine, even at room temperature. At fridge temps I bet they'll last even longer.

[lowendfrequency]

The trouble with the autolysis topic is it's subjectivity. Many people have a difficult time identifying the off-flavors produced (which I can only really describe as "organic-decay"). Because of this, there is a lot of autolysis deniers and heated debates surrounding the subject. Bottom line though, autolysis is real. Very much so. Autolysis is the process at work behind the act of aging wine on it's lees to create a vintaged cuvee. If you are serious about brewing and the quality of your beer, then you'll take autolysis seriously as well. It might not be the defining difference between good beer and great beer, but it most definitely plays a factor. Also, just a note. Autolysis is directly tied to volume/surface/contact area with your yeast. Your fermenter shape and size will greatly influence the rate at which the off-flavors are produced. Homebrewing vessels tend to emphasize this problem compared to taller commercial conicals. Homebrewers also generally underpitch and ferment slowly as a result, leaving their beer in contact with their yeast longer, which doesn't help either.

[strangebrewer]

In the world of wine making we call it Sur Lie aging. By the fact that it has a much more suave and chic name it is not harmful at all and is in fact beneficial.I won't start on the subject of autolysis and brettanomyces

[CaptRon]

The trouble with the autolysis topic is it's subjectivity. Many people have a difficult time identifying the off-flavors produced (which I can only really describe as "organic-decay"). Because of this, there is a lot of autolysis deniers and heated debates surrounding the subject. Bottom line though, autolysis is real. Very much so. Autolysis is the process at work behind the act of aging wine on it's lees to create a vintaged cuvee. If you are serious about brewing and the quality of your beer, then you'll take autolysis seriously as well. It might not be the defining difference between good beer and great beer, but it most definitely plays a factor. Also, just a note. Autolysis is directly tied to volume/surface/contact area with your yeast. Your fermenter shape and size will greatly influence the rate at which the off-flavors are produced. Homebrewing vessels tend to emphasize this problem compared to taller commercial conicals. Homebrewers also generally underpitch and ferment slowly as a result, leaving their beer in contact with their yeast longer, which doesn't help either.

Reading this, I can only conclude that my impatience is going to help prevent autolysis from being a problem. I'm like a little kid waiting for his birthday to come from the point of heating my strike water until my first pint.

[MtnBrewer]

Temperature has to be a big factor. I keep yeast samples around in the fridge for 6-7 months without doing anything with them sometimes and they've been fine. Also - consider bottles with yeast sediment in them - seem to be fine, even at room temperature. At fridge temps I bet they'll last even longer.

Yeah, very good point. Temperature is a major factor. Like most chemical reactions, it happens much faster at higher temps. This may in fact be the reason that people were so paranoid about it back in the bad ol' days. There was much less temperature control then.

[Jimmy James]

Autolysis is a term thrown around a lot in brewing circles but it doesn't really have any consistent definition that I can put my finger on. If you look at wikipedia there's a crappy article with two references, neither of which refer to brewing beer from what I can tell. If you mean yeast dying then yes, at some point they do. However, in most fermentations the yeast will simply flocculate and go dormant first, and stay that way for a good while. You drink a hefe weizen that was bottled in Germany with a good sized slug of yeast in the bottom probably 6 months ago (or more) and you swirl the yeast up and pour into your glass - does it make your hefe taste like burnt rubber or meat? No it doesn't. Apoptosis (programmed cell death) happens all over in nature. If it didn't you'd have a stump for a hand instead of fingers and a thumb. Cells die when they get certain biochemical signals. If autolysis is something like that run out of control then it'd result in the entire yeast population dying off rather quickly and ruining your beer.

[MtnBrewer]

If you mean yeast dying then yes, at some point they do.

No, that's not what it means. See some of the above posts for the correct definition.

[CaptRon]

Dying yeast is part of it, but from what I'm getting from this is that it is byproduct of live yeast consuming the dead yeast.

[Jimmy James]

No, that's not what it means. See some of the above posts for the correct definition.

I am not clear as to what it means from this thread or any other thread I've read. The two popular definitions I've seen are:1. Self-cannibalization due to starvation2. Recycling of dead tissue by living tissueAre we going with one of those definitions or something else?

[ThroatwobblerMangrove]

I am not clear as to what it means from this thread or any other thread I've read. The two popular definitions I've seen are:1. Self-cannibalization due to starvation2. Recycling of dead tissue by living tissueAre we going with one of those definitions or something else?

Those sound pretty similar to me. #2 is just a more PC way of saying #1 (or something).

[CaptRon]

I am not clear as to what it means from this thread or any other thread I've read. The two popular definitions I've seen are:1. Self-cannibalization due to starvation2. Recycling of dead tissue by living tissueAre we going with one of those definitions or something else?

Number 1 leads to number 2 is the way I understand it. Now you got me confused

[Jimmy James]

If it's both fine. Either way, I don't see how it can happen in your fermentation unless you introduce something like heat. If starvation triggered it you'd get autolysis immediately upon hitting final gravity. But you don't - the yeast go dormant. Are we supposed to believe they all wake up 6 months or a year later and decide to pop? They probably do indeed cannibalize somewhat, but that would reduce any effect of autolysis I would think.I am skeptical about autolysis in beer - I think it can happen perhaps, but if it was such a big problem I don't think I'd be able to pop so many aged bottle-conditioned beers and imported hefe-weizens and have them tasting so good.

[earthtone]

Main Entry: 1au·to·mat·ic Pronunciation: \ˌȯ-tə-ˈma-tik\Function: adjective1 a : largely or wholly involuntary; especially : reflex 5 <automatic blinking of the eyelids> b : acting or done spontaneously or unconsciously c : done or produced as if by machine : mechanical <the answers were automatic>Main Entry: ly·sis Pronunciation: \ˈlī-səs\Function: noun1 : the gradual decline of a disease process (as fever)2 : a process of disintegration or dissolution (as ofMain Entry: au·tol·y·sis Pronunciation: \-lə-səs\Function: noun: breakdown of all or part of a cell or tissue by self-produced enzymes— au·to·lyt·ic \ˌȯ-tə-ˈli-tik\ adjectiveAutolysis, from a biological perspective, is literally the lysis (rupture) of a cell due to the lysosomes (the "stomach" organelle filled with digestive enzymes) emitting all their proteases and other digestive enzymes into the cell allowing them to dissolve the cell. This occurs when salt is added to live yeast, and is one way of making vegemite. Prolonged amounts of time in a toxic environment (ie. alcohol rich beer) will eventually also cause the lysosomes to rupture, digesting all remaining barriers between the beer and the cell organelles and the result is an increase in nitrogen rich compounds (like those that come from proteins like DNA, RNA and all the other cellular machinery). This can be desireable in some kinds of wine - HERE is a great .pdf explaining why some wines are aged on the lees to encourage autolysis as a desirable addition to a wine.