Autolysis Myth - BUSTED

[HokieBrewer]

Assuming he washed it correctly. Either way 6th gen yeast is different than the initial fermentation.

 

[Starderup]

Assuming he washed it correctly. Either way 6th gen yeast is different than the initial fermentation.

I am completely in agreement. Every time you touch yeast, you are risking contamination. I'm all for reusing or washing yeast to save money, but not when it might cost you $25 to save $3.

I have done the parallel culturing, and that is an awesome way to maximize your investment. The benefit of it is that all your resultant yeast is second generation at the most. IMHO, it is really 1st, but some people count that initial culture as 1st.

 

[remilard]

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.

Get a pH meter. The pH will drop during fermentation, be stable for a while, and then start to rise. When it rises, yeast are lysing. This is temperature and yeast cake depth dependent but in reasonable conditions and subject to the accuracy of a homebrew grade meter this does take on the order of weeks (weeks not months) to occur in hombrew.

In commercial cylindroconical tanks with a yeast depth of a couple of feet it can happen in days.

Autolysis isn't a myth, the idea that autolysis is evidenced by fecal or rubber aromas is. For lack of a better term, autolysis contributes umami (free glutamate). This can range from nutty and bready flavors you wouldn't notice in beer (but are noticeable and desired in sparkling white wine and mead) to brothy or meaty flavors that are notable in aged stout and barleywine or in Marmite/Vegemite.

 

[pjj2ba]

Autolysis isn't a myth, the idea that autolysis is evidenced by fecal or rubber aromas is. For lack of a better term, autolysis contributes umami (free glutamate). This can range from nutty and bready flavors you wouldn't notice in beer (but are noticeable and desired in sparkling white wine and mead) to brothy or meaty flavors that are notable in aged stout and barleywine or in Marmite/Vegemite.

Correct! It is only an off-flavor if you don't like it. Many folks are drinking beers that are affected by autolysis and are loving them! Heck, I might even go as far as to say a large percentage of homebrewers like the flavors

Palmer's book has perpetuated the nasty flavor myth. He had a nasty stinky pot of homemade rice glue that went bad and exclaimed, "Ahah, this must be yeast autolysis!" even though he had no evidence that this was the case (no added yeast btw). So now people don't detect these nasty flavors in their beers so they say, yup, no autolysis, when in fact all it means is that they didn't have a nasty infection like in that forgotten rice glue pot

 

[ArcLight]

What about a long primary fermentation in a plastic bucket?
Any problems with leaviung it in an Ale Pale or some similar plastic food garde bucket (sold by a reputable brew supply store) for 4-6 weeks?

 

[jkreuze]

I have three different five-gallon batches of homebrew that need kegging, ranging from probably three to five months of sitting on yeastcake. I'll see if I can get motivated to keg some beer today (seems to fit the theme of the thread) and we will see how it is coming along.



Leaving your stuff in an ale pail for 4-6 weeks should be fine.

 

[MachineShopBrewing]

Correct! It is only an off-flavor if you don't like it. Many folks are drinking beers that are affected by autolysis and are loving them! Heck, I might even go as far as to say a large percentage of homebrewers like the flavors

I agree. Its just like how most brewers don't think they have an oxidation problem, when they have just become used to the flavors and don't realize that they do. Or the post you see where some guy pitched a six month old yeast cake and it happens to ferment, so the person proclaims that there is no problem with using six month old yeast cakes.

Am I saying that you can't leave the beer on the yeast for longer than 4 weeks? Absolutely not. Some people are content with their process and it works for them. That's fine, just don't run around and say that its the only way to do it and that there is no yeast dying in there.

 

[BillyBroas]

Get a pH meter. The pH will drop during fermentation, be stable for a while, and then start to rise. When it rises, yeast are lysing. This is temperature and yeast cake depth dependent but in reasonable conditions and subject to the accuracy of a homebrew grade meter this does take on the order of weeks (weeks not months) to occur in hombrew.

Good idea. I was planning to buy a pH meter soon anyways.

 

[cox8611]

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.

...the rubber cement smell is unmistakable.

Trust me, that is VERY accurate. I rehydrated US-05 in a sanitized growler for 2-weeks after thinking I would need it to help something ferment out, but ended up leaving it in growler, only rehydrated with water....

needless to say opening that thing was a HORRIBLE mistake indoors. tossed that bad boy outside and bleached the growler and all is well. however, i Have never had any yeast on top of some form of wort/beer go bad like that did. The particles/nutrients in the wort help the yeast go dormant and not autolyze.