Autolysis Myth - BUSTED

[Torchiest]

Okay, I've been WAY out of the brewing scene ever since my wife had our first child on Superbowl Sunday. The last batch I brewed was a couple weeks before he was born, and I FINALLY today am transferring it to a keg. The original gravity was 1.066. Today, I checked it, and it's 1.012. 7% ABV. It's a Belgian Porter.

I wanted to post this because everyone worries about nasty flavors from dying yeast, but I'm here to say that fear is extremely overblown. I left this thing completed untended in primary for 139 days, and it tastes awesome. While 1.066 OG is fairly strong, it's nothing that crazy, and when I checked the gravity a few months ago, it was already down to 1.013, so it's done very little additional fermentation in the meantime.

Anyway, point is, you can leave a beer safely in primary for months without worrying about dead yeast. Just thought people would be interested in hearing about my experience, as it was a good one. And now I finally get keg beer again. The next step is to figure out how to brew beer while holding a four month old baby. :rockin:

 

[Priemus]

Wow thats a long time to wait, Awesome result.

I never make anything complicated enough to warrant such a long ferment, although I did hear that Samichlaus beer ferments for 10 months, if that doesnt cause problems I dont know what will.

edit:

Grats on the Baby as well as the beer

 

[Torchiest]

Haha, the long ferment time was definitely not planned! SWMBO thought the batch was doomed for sure.

 

[Priemus]

Karma, seeing as it shares a date with the newest member of your family make sure you put one aside for him/her for another 17 and a half years

 

[Airborneguy]

Congrats on the baby and thanks for the tip. When mine comes (October), I'm praying I don't have to take a long break.

 

[curlyfat]

The next step is to figure out how to brew beer while holding a four month old baby. :rockin:

Luckily, babies have cribs, and beer mugs have handles...guess which one you can set down! Just kidding. Congrats the baby and the brew, enjoy the ride!

 

[Starderup]

I can also verify that yeast is a hardy animal. I saved most of the refrigerated yeast cake from a Coopers IPA brewed about a month ago. Washed it, pitched it into some leftover wort, and it is absolutely taking off.
Hardly any dead yeast, and now I got to figure out a brew to use it on.

 

[Brocster]

The next step is to figure out how to brew beer while holding a four month old baby. :rockin:

That is what Baby Bjorn's are for.

 

[ChshreCat]

This should be a sticky!

 

[2-0turbo]

I have a similar story. I brewed an Octane IPA from a Midwest kit and then hurt my back. I wasn't able to lift, move or anything for a couple months. My beer sat in the fermenter for 16-weeks on the yeast and it also, was fantastic. Granted, I don't think my taste is refined enough to be able to taste the effects of yeast autolysis, but the beer was really good. I'm not as worried about it these days after my little "experiment."

 

[Torchiest]

Granted, I don't think my taste is refined enough to be able to taste the effects of yeast autolysis, but the beer was really good.

Trust me, from what I've heard, you don't need refined anything to detect autolysis. It smells like a dead animal stuffed in a tire, I believe.

 

[remilard]

Trust me, from what I've heard, you don't need refined anything to detect autolysis. It smells like a dead animal stuffed in a tire, I believe.

Ever had Marmite, Vegemite or Champagne?

 

[pjj2ba]

The myth is that autolysis leads to strong nasty flavors. To get the yeast to make those kind of flavors you really need to abuse it. Things like extra oxygen after fermentation is complete, high temperatures, and probably also requires some kind of infection.

Autolysis is a normal part of the yeast life cycle. Once a yeast culture has reached stationary phase (vigorous fermentation has ceased), some of the yeast will start to autolyze. In the lab, this is absolutely occuring so I don't think this is somehow miraculously not occurring in beer. The myth is that it creates strong nasty flavors.

I think it was an unfortunate coincidence and there was something else going on in a bad batch of beer and someone said "Oh, it must be autolysis", and the terminology stuck. I'm sure that was going on, but there were other mitigating factors as well.

I congratulate the OP on taking good care of his yeast!

 

[Torchiest]

Good post. My main thrust was that the dangers are way over-hyped, and a typical batch won't encounter any problems even if left alone for multiple months. In fact, my experience is in line with the great John Palmer:

10.3 Autolysis

 

[HokieBrewer]

If anything, I think there's more harm in racking the beer out of primary too early. My first IPA was 1.06x and I bottled it after two weeks. It took a few more weeks for the off-flavors to clear up.

Patience is a virtue in this hobby.

 

[pjj2ba]

Good post. My main thrust was that the dangers are way over-hyped, and a typical batch won't encounter any problems even if left alone for multiple months. In fact, my experience is in line with the great John Palmer:

10.3 Autolysis

Actually, that section by Palmer is what I have a big problem with.

He made the assumption, that of all the microbes floating around in the air it was a yeast that settled into the open pot of rice glue. There are plenty of microbes out there that can do fermentation, and some natural yeast that are pretty funky too. Actually any organism breaking down sugars is going to release CO2 and cause bubbles in a liquid. This was not wort with hops in it to help limit what would grow in it. This is like leaving a pot of Mac and cheese on the stove for a week and then seeing it growing and smelling nasty. Yup, must be yeast autolysis.

I was just reading an article in Science News about human fungal infections (not common) and they say, "A 2005 study found that about a million spores are nestled in your pillow alone." And that is just fungus. There are probably even more bacteria, which will happily do fermentation too.

 

[GilaMinumBeer]

My impression has always been that autolysis is more an issue to long term bottle conditioning rather than bulk fermentation.

 

[BillyBroas]

Actually, that section by Palmer is what I have a big problem with.

Yea that section wrongfully scares a lot of people. He actually admitted that the information is out of date, and corrected it in the later editions of the book. The web version is still the 1st version though, and unfortunately tons of people still use it w/o realizing what has changed.

We discuss this here, but I'm not surprised by the results in the OP. Great to see actual results though.

 

[david_42]

Granted, I don't think my taste is refined enough to be able to taste the effects of yeast autolysis,

Believe me, one does not need refined taste buds or a good sense of smell in this case. I've created autolyse once, left a yeast cake on the back porch for two months, in the summer. Open cesspool would be a polite way to describe it.

 

[Starderup]

Yea that section wrongfully scares a lot of people. He actually admitted that the information is out of date, and corrected it in the later editions of the book. The web version is still the 1st version though, and unfortunately tons of people still use it w/o realizing what has changed.

We discuss this here, but I'm not surprised by the results in the OP. Great to see actual results though.

The other myth that needs serious busting is "Never, ever, leave your beer in the primary more than 14 days. Otherwise, you will get oxygen contamination and your beer will be ruined." It seems that Revvy has been leaving beer in the primary fermenter for a month, and winning awards with ruined beer. :cross:

 

[shanecb]

Hear, hear! The fears of autolysis really are overblown (in my experience with meads, at least), and I have to agree with Starderup's point about leaving things in primary.

 

[balazs]

Okay, I've been WAY out of the brewing scene ever since my wife had our first child on Superbowl Sunday. The last batch I brewed was a couple weeks before he was born, and I FINALLY today am transferring it to a keg. The original gravity was 1.066. Today, I checked it, and it's 1.012. 7% ABV. It's a Belgian Porter.

I wanted to post this because everyone worries about nasty flavors from dying yeast, but I'm here to say that fear is extremely overblown. I left this thing completed untended in primary for 139 days, and it tastes awesome. While 1.066 OG is fairly strong, it's nothing that crazy, and when I checked the gravity a few months ago, it was already down to 1.013, so it's done very little additional fermentation in the meantime.

Anyway, point is, you can leave a beer safely in primary for months without worrying about dead yeast. Just thought people would be interested in hearing about my experience, as it was a good one. And now I finally get keg beer again. The next step is to figure out how to brew beer while holding a four month old baby. :rockin:

Good Stuff!!!! I had a feeling that was overblown...Anyways, I know how them little munchkins can take up pretty much all of your free time for a long long long time. Have fun brewing away.

 

[Piotr]

I'm sorry, I have to de-bust the autolysis myth.
Autolysis exists.
This comes from a competition scoresheet of my German Pils (rude translation):

... the beer is generaly very correct, except for strong autolysis, both in aroma and flavour (baked patato, burned milk)....

The beer was 4 weeks on pimary in 50F. Yeast : Bohemian lager slurry, 5th harvest, the slurry was washed and very fresh (1 day after harvest)

 

[jsweet]

That doesn't really prove anything, though. It's completely possible that the judge was detecting some other off-flavor, which she has been taught to identify as autolysis. (Did she inspect your beer under a microscope and find an excess of ruptured yeast cells?)

Similarly, the OP's unintentional experiment doesn't really prove anything either, except that an absurdly long primary does not necessarily result in bad beer. With the lack of any sort of rigorous experimentation, all we can assert with certainty is this: Most, but not all, people who have attempted long primaries have been happy with the results.

The could mean any number of things: a) long primaries only sometimes cause autolysis; b) autolysis is caused by some other factor that is exacerbated by long primaries; c) long primaries don't cause autolysis, but they sometimes cause some other problem that is falsely labeled autolysis; d) long primaries have nothing to do with it, but some completely unrelated problems are sometimes falsely labeled autolysis; e) long primaries cause autolysis, but depending on the style and/or taster it may not always be particularly detectable in the flavor; f) long primaries cause autolysis only under certain conditions; etc. We really can't tell between those alternatives with the data we have.

Like I say: All that can be stated with certainty is that many, but not all, people who have tried long primaries are happy with the results. Until more rigorous data is available, that means each brewer will have to make their own decision.

Edit: Oh, and the one thing the OP's experiment proves is that this phenomenon whereby many (but not all) people who attempt long primaries are happy with the results, that appears to extend to really absurdly long primaries, like the OP's 20 weeks.

 

[Starderup]

4 weeks is nowhere near long enough for that to happen. You do have to remember that judges are not perfect. I routinely leave my beers in the primary for 4-6 weeks. It does nothing but let the yeast finish and clean up, and also clears the beer.
This has been my consistent experience, and have never had those flavors at all. YMMV.

 

[BillyBroas]

Like I say: All that can be stated with certainty is that many, but not all, people who have tried long primaries are happy with the results. Until more rigorous data is available, that means each brewer will have to make their own decision.

Good points. I'm perfectly happy with long primaries but the geek in me would also like to see some experiments that show the cell death rate over time in the fermentor.

 

[shanecb]

The beer was 4 weeks on pimary in 50F. Yeast : Bohemian lager slurry, 5th harvest, the slurry was washed and very fresh (1 day after harvest)

Unless the yeast were really stressed out or there was some sort of fermentation issue, 4 weeks isn't nearly enough time for autolysis to occur.

 

[paraordnance]

I'm sorry, I have to de-bust the autolysis myth.
Autolysis exists.
This comes from a competition scoresheet of my German Pils (rude translation):

... the beer is generaly very correct, except for strong autolysis, both in aroma and flavour (baked patato, burned milk)....

The beer was 4 weeks on pimary in 50F. Yeast : Bohemian lager slurry, 5th harvest, the slurry was washed and very fresh (1 day after harvest)

I have hard time believing that sorry, since I just did experiment for myself - fermented (2 weeks) and lagered (3 weeks) all in same vessel, in carboy, on yeast (wyeast 2206). It is Vienna Lager and I cannot detect any off-flavours

 

[HokieBrewer]

Yeast : Bohemian lager slurry, 5th harvest

I think this is the key point no one is noticed. Were you pitching onto an old yeast cake repeatedly? After 5 batches on the same cake, and then fermented for 4 weeks, this could be true...

 

[rockfish42]

I think this is the key point no one is noticed. Were you pitching onto an old yeast cake repeatedly? After 5 batches on the same cake, and then fermented for 4 weeks, this could be true...

Since he washed it it should be fine.