Further de-bunking autolysis

[Jack]

My smoked stout spent six months and one day in the primary. I started going back to school (on top of working >50 hours/week), and I kind of lost track of time.

Anyway, no sign of off-flavors at bottling time. I pitched another envelope of Wyeast 1084 at bottling time just to make sure it carbonated.

While I wouldn't advocate letting beer sit for that long (normally I don't have that kind of patience!), I don't think I'm going to be worrying about autolysis anymore.

 

[ArcaneXor]

Autolysis definitely exists, but when it sets in depends on a lot of circumstances, so there is no set guideline for how long the yeast is safe before it goes bad. But once you do taste autolysed beer, you'll never forget the taste - it's very unique, almost brothy.

 

[Scut_Monkey]

I think I've had wine with autolysis. My wife and I drank a wine that honestly tasted like burning tires. An extremely strong and disguisting flavor. I have no idea how else such a flavor could have gotten into the wine. Maybe it was autolysis maybe not but that wine sucked a$$.

 

[FlyGuy]

Autolysis is not a myth. It is most detectable in light, delicate beers that have a hard time hiding off-flavours.

I wouldn't call your batch light and delicate. You could hide a lot of off flavour in a smoked stout. Are you SURE you didn't get autolysis?

 

[Jack]

Yeesh. I know autolysis exists. I work with enough microbiologists to know that.

After being told for five months that my beer was surely ruined, I was just surprised by how clean and crisp the flavors turned out.

Are you SURE you didn't get autolysis?

If there's an imperfection in your beer that can't be perceived, is it really an imperfection?

 

[Chuck_Swillery]

If there's an imperfection in your beer that can't be perceived, is it really an imperfection?

Very true! LOL

 

[FlyGuy]

If there's an imperfection in your beer that can't be perceived, is it really an imperfection?

Ah, but that's not what your original post asserted! You said that you were 'de-bunking autolysis' and that you would not worry about it again.

Perhaps you should worry, if you ever make a light delicate beer (e.g., a kolsch). That is the only point I was trying to make -- don't generalize your results too broadly when you are experimenting with the extremes.

 

[remilard]

I think I've had wine with autolysis.

You almost certainly have. The flavor of Champagne and similar sparkling white wines is dominated by autolysis flavors.

As for the OP, this is more like an anecdote than a debunking.

Steve Parkes of the American Brewers Guild wrote in the current BYO that home brewed beer often has off flavors from autolysis. While I wouldn't go that far, I think it is not at all rare.

The perception that autolysis doesn't occur is, IMO, primarily due to an unfounded belief (perpetuated by home brewing books) that autolysis is always accompanied by high levels of mercaptans or sulphur containing compounds. In a nutshell, Palmer wrongly told you that autolysis tastes like poop so as long as you don't taste poop you believe there is no autolysis.

 

[cheezydemon3]

I have an IPA that was in the primary 3 months or so.

I guess the bitterness will hide some, but it is fairly pale.

 

[XXguy]

You almost certainly have. The flavor of Champagne and similar sparkling white wines is dominated by autolysis flavors.

as long as you don't taste poop you believe there is no autolysis.

Interesting, until I read your post, I would say that I've never tasted autolysis. I've always heard it described as foul or raunch.

Now I'm wondering just exactly is the flavor/taste of autolysis & what is the threshold between "evident" and "foul". Obviously, Champagne never would have become popular if people thought it tasted foul.

That comment really makes me curious .

 

[FlyGuy]

The perception that autolysis doesn't occur is, IMO, primarily due to an unfounded belief (perpetuated by home brewing books) that autolysis is always accompanied by high levels of mercaptans or sulphur containing compounds. In a nutshell, Palmer wrongly told you that autolysis tastes like poop so as long as you don't taste poop you believe there is no autolysis.

I don't see anywhere in How To Brew where Palmer says autolysis tastes like poop. Nor do I see where he associates mercaptans or sulphur with autolysis. He associates these with other causes (e.g. mercaptans are the principle component of skunky aromas in light-struck beer).

Palmer describes autolysis as POTENTIALLY (not always) leading to some of the following aromas/flavours, although I do think he exaggerates how bad these will be, even with mild autolysis:
- yeasty (think under-cooked bread)
- rubbery, or burnt rubber
- meaty or brothy

 

[Jack]

Ah, but that's not what your original post asserted! You said that you were 'de-bunking autolysis' and that you would not worry about it again.

I didn't realize that Homebrew Talk was for scholarly studies only. My bad.

Look, if you want a study on this, go for it. Have a double-blind validated tasting panel try a sample of similar beers (same recipes/ingredients/brewing techniques/brewer/equipment/temperatures, different time on the lees). The effect of batch-to-batch variation and aging time would have to be accounted for in your statistical analysis. If autolysis is a major concern, the perception of autolysis off-flavors should strongly correlate to time spent in contact with precipitated yeast. Or better yet, perform a LC-mass spec or headspace GC-mass spc study and the effects could be quantitated more accurately and the statistics would be a lot tighter. Of course, you'd need to do mass spec-olfactory characterization which would assist with peak identification.

You could also put the same yeast sediment on the bottom of several containers and rack a rather insipid lager ontop of it. After say 1 week, 5 weeks, and 10 weeks you could rack the beer off the yeast and put it into a clean container. They would all have the same age and the insipid lager would not hide off-flavors.

In addition, the perception of autolysis-related off-flavors may well be dependent upon style, with some styles masking the effect.

Do all of that and get back to me with the results. Ok?

I didn't do that study. I just brewed a beer and made a post on the internet saying that I liked it, which went against both conventional wisdom and my own expectations. I thought other people might benefit from this information.

And yes. My one data point suggests that autolysis is not a concern on the scale of days as is often suggested in the homebrewing community, but takes substantial amounts of time to contribute off-flavors to beer.

 

[FlyGuy]

Sorry Jack -- I didn't mean to be argumentative nor did I mean to trivialize your report. Thanks for providing this info, because as you have pointed out, we need to hear about the range of outcomes from many homebrewers brewing various styles, gravities, etc. before we can determine the extent of potential autolysis effects in our beer.

 

[starrfish]

left a mead in primary for 6 mo... which was too long. had a yeast bite (sulphury bitterness) that never aged out, even after 3 years.

But Mead is a different animal using champagne yeast.

no autolysis or ANY Badness with beer in primary for over 30 days...

 

[remilard]

Interesting, until I read your post, I would say that I've never tasted autolysis. I've always heard it described as foul or raunch.

Now I'm wondering just exactly is the flavor/taste of autolysis & what is the threshold between "evident" and "foul". Obviously, Champagne never would have become popular if people thought it tasted foul.

That comment really makes me curious .

https://www.homebrewtalk.com/f14/autolysis-101230/

Few good links posted in that thread. In general, look for literature from wine making as they study yeast autolysis more since they intentionally use it in some styles.

 

[pjj2ba]

You almost certainly have. The flavor of Champagne and similar sparkling white wines is dominated by autolysis flavors.
The perception that autolysis doesn't occur is, IMO, primarily due to an unfounded belief (perpetuated by home brewing books) that autolysis is always accompanied by high levels of mercaptans or sulphur containing compounds. In a nutshell, Palmer wrongly told you that autolysis tastes like poop so as long as you don't taste poop you believe there is no autolysis.

Palmer describes autolysis as POTENTIALLY (not always) leading to some of the following aromas/flavours, although I do think he exaggerates how bad these will be, even with mild autolysis:
- yeasty (think under-cooked bread)
- rubbery, or burnt rubber
- meaty or brothy

Both remilard and FlyGuy are on the mark! What I think is in need of de-bunking is the flavors associated with autolysis. These flavors cover the whole spectrum from light bready flavors (good in some styles) to gag nasty, rotten flavors. The problem is way too many people have it in their head that the flavor of autolysis is only the latter, so they say it doesn't exist.

In reading of scientific journal articles on wine making, the scientist have shown that autolysis begins to occur once the bulk of fermentation has been completed. Working in a lab (yeast and other microbes) I know that this starts to occur once stationary phase has been reached. I see no reason why beer fermentation should be any different. To re-state, the myth about autolysis is not whether it exists, it clearly does, the myth is that it always leads to strong nasty flavors.

I'll have to do some looking through the beer lit. to see if similar studies have been done

 

[Jipper]

I think the main point the OP was saying was he won't stress about beers that have been on the yeast for long periods of time, and to never count a batch out! Glad to hear you saved it.

I actually leave my mead on the yeast bed for 6 months to a year. I find that with the yeast i use - white wine yeast - it gives a soft nutty character to the mean that is quite complementary. I have also had meads on the yeast for 3 years that are some of the best I have ever had. Depends on the yeast, I think.

 

[XXguy]

OK - so I went & did some reading. One line that stuck out to me was this:

There are several reasons as to why a winemaker may choose the "sur lie" method ofwine production. The most important reason being the influence of yeast lees on theorganoleptic properties of wine. The wine is often described to have enhanced body, creamier, richer, mouth feel, greater complexity and depth of flavor, and a better integration of fruit-and-wood-derived components

Now, I realize they're talking about wine, but all those items seem like they'd be beneficial, not detrimental. My understanding was that Autolysis was always described as a flaw in beer, now I'm thinking it's a much more complex topic.

 

[LeftyGorilla]

Hope this is not thread-jacking, but I've been wondering for a while now about autolysis in regard to champagne yeast.

I've got a mead on champagne yeast (in retrospect probably a bad idea, but what's done is done) it's been happily bubbling away for a week now. I'm planning to bottle it sometime early march. I understand with champagne yeasts that sitting on the lees is an important part of the fermentation process. It turned out over 1.110 SG and I think it will take a while to mellow out. I was thinking 9-12 months.

For this long mellowing in the bottle, should I make sure is some inert yeast from the primary ferment to get the full (beneficial) effect of autolysis? I'm not planning on riddling these and icing out the lees unless I go totally nuts between now and next fall.

Anybody have general thoughts on this? I've been googling, but can only find info on (real) champagnes, not meads, etc.

 

[Bopper]

I've left apfelwein in primary for 7 months with not even a slight hint of autolysis. Not saying it doesn't happen, just giving my experience.

 

[Jipper]

Hope this is not thread-jacking, but I've been wondering for a while now about autolysis in regard to champagne yeast.

I've got a mead on champagne yeast (in retrospect probably a bad idea, but what's done is done) it's been happily bubbling away for a week now. I'm planning to bottle it sometime early march. I understand with champagne yeasts that sitting on the lees is an important part of the fermentation process. It turned out over 1.110 SG and I think it will take a while to mellow out. I was thinking 9-12 months.

For this long mellowing in the bottle, should I make sure is some inert yeast from the primary ferment to get the full (beneficial) effect of autolysis? I'm not planning on riddling these and icing out the lees unless I go totally nuts between now and next fall.

Anybody have general thoughts on this? I've been googling, but can only find info on (real) champagnes, not meads, etc.

Try to bottle a couple with some yeast in it, just as a trial.

 

[LeftyGorilla]

Try to bottle a couple with some yeast in it, just as a trial.

Yeah.

I'm planning on 3 or 4 champagne bottles with the rest in 7oz shorties for sampling to determine readyness. It's an experimental batch, so I guess I should experiment.

 

[remilard]

Hope this is not thread-jacking, but I've been wondering for a while now about autolysis in regard to champagne yeast.

I've got a mead on champagne yeast (in retrospect probably a bad idea, but what's done is done) it's been happily bubbling away for a week now. I'm planning to bottle it sometime early march. I understand with champagne yeasts that sitting on the lees is an important part of the fermentation process. It turned out over 1.110 SG and I think it will take a while to mellow out. I was thinking 9-12 months.

For this long mellowing in the bottle, should I make sure is some inert yeast from the primary ferment to get the full (beneficial) effect of autolysis? I'm not planning on riddling these and icing out the lees unless I go totally nuts between now and next fall.

Anybody have general thoughts on this? I've been googling, but can only find info on (real) champagnes, not meads, etc.

I would read the wine, particularly sparkling white wine, literature as they are the experts on this. One thing I have picked up is that wine makers associate sulphuric and mercaptan flavors with lees 4" in depth or more, and they stir the lees back into the wine somehow to avoid settling to a greater depth. Home brewed batches would rarely have lees at that depth.

To get the prominent autolysis flavor characteristic of champagne you are looking at 5-10 years in the bottle on the lees.

 

[Jipper]

I wonder how much is strain dependent. Do the flavors that bind with wine yeast differ from the ones that beer yeast do? It's be interesting to make a mead with beer yeast - a lighter one - and age that on the lees for 6 months, and do a side-by-side with some wine yeast.

 

[LeftyGorilla]

I would read the wine, particularly sparkling white wine, literature as they are the experts on this. One thing I have picked up is that wine makers associate sulphuric and mercaptan flavors with lees 4" in depth or more, and they stir the lees back into the wine somehow to avoid settling to a greater depth. Home brewed batches would rarely have lees at that depth.

To get the prominent autolysis flavor characteristic of champagne you are looking at 5-10 years in the bottle on the lees.

I may have overpitched, but I swear in a 1 gal batch there is currently 2-3 inches after a week. it's pretty loose, but it's thick.

5-10 sounds like a very long time...I thought the minimum required by law was more like 1.5 years.