Stuck Fermentation

[Dutto]

............

Anyway as far as aerating wort is concerned I've put forward my opinion earlier on here as did other people, and looking back some of us don't bother with it at all! ............

Er .... would that be the ones who finish up with a stuck brew? :whistle:

If you Google "aerating a wort in brewing" you will get about 133,000 hits; most of which (TBH I haven't read all of them) advocate aeration of the wort as being a good thing.

Enjoy! :thumb:

 

[Sadfield]

Er ..... please explain your 12% upper limit v. a Turbo Yeast which will produce a 20% ABV.

https://www.brew2bottle.co.uk/still...MIo6-WgLnZ1wIVirvtCh0Q1ADLEAQYAyABEgJykPD_BwE

Apart from it being a specially bred least the packet apparently also contains nutrients that produce O2.

:thumb: :thumb:

Ha, thanks for even further emphasising my point that yeast is alcohol tolerant, even at 20%. Now, explain your theory that in the lower abv of a stuck mash, fermentation has stopped because the alcohol has killed the yeast.:lol:

 

[Dutto]

Ha, thanks for even further emphasising my point that yeast is alcohol tolerant, even at 20%. Now, explain your theory that in the lower abv of a stuck mash, fermentation has stopped because the alcohol has killed the yeast.:lol:

I have NEVER said that.

Indeed, I pointed out ...

"I understand that 1. is very rare in beer brewing but can occur with wines if the yeast has an alcohol tolerance that is lower than that required for complete fermentation of the wine."

Please go back and read my threads!

 

[LarryF]

A teaspoon of yeast nutrient stirred in may help revive the yeast, failing that boil some raisins crushing them while they boil then strain and stir the liquid into the wort when cooled. I've done a few Wherry's ( the memory of them being £16 in the Tesco sale still brings a tear to my eye) but never used the kit yeast, one thing I will say about the kit yeast.....it makes great bread.

 

[Sadfield]

I have NEVER said that.

Indeed, I pointed out ...

"I understand that 1. is very rare in beer brewing but can occur with wines if the yeast has an alcohol tolerance that is lower than that required for complete fermentation of the wine."

Please go back and read my threads!

OK, I did.....

The yeast provided in a kit is often a bit past its "Use By" date. If the yeast has died then the fermentation process will not start, however this is very rare and with old yeast it can take quite a time for a brew to get going.

However, after a slow start and given enough sugar and oxygen the yeast will reproduce until such time as the sugar is consumed OR the oxygen is depleted OR the ABV reaches a point that the yeast cannot tolerate and dies.

Yep, you definitely said it in a thread about stuck fermentation, directly after referencing kit brews, in the General Beer Brewing Discussion forum.

 

[Dutto]

OK, I did.....



Yep, you definitely said it in a thread about stuck fermentation, directly after referencing kit brews, in the General Beer Brewing Discussion forum.

Please read through my Posts again and this time read them with a view to understanding what they say rather than trying to pick holes in the statements.

My statement was that the condition is "VERY RARE IN BEER BREWING"!

As an example of when it can occur, I have seen numerous questions on this Forum where a person new to brewing has asked if the addition of more sugar than that recommended in a particular kit (especially the "one-can" kits) will increase the ABV.

Of course it will, BUT the increased amount of sugar may take the yeast into a range of ABV that it cannot tolerate. I have yet to see the addition of more sugar recommended, which may account for the fact that IT IS VERY RARELY THE CAUSE OF A STUCK FERMENT IN BEER BREWING!

 

[Sadfield]

So in a thread regarding a stuck fermentation from an OG 1.040, I now have to view your ill informed posts in the context of some freak situation that never happens just to now make it vaguely valid. Priceless. I had no need to pick holes, they were big enough for you to fall through them. It's is clear you don't understand why fermentation stalls in any brewing situation.

 

[pms67]

Bloody hell guys,does it matter that much??????
Let’s end this pissing contest,it’s the last time anyone will ask about a stuck brew again,the only thing that’s stuck is this thread 😉

 

[Sadfield]

Or we could try stopping them being stuck in the first place.

Pissing contest? You'd rather everyone just post anything, unsubstantiated, unchallenged?




Sent from my E5823 using Tapatalk

 

[pms67]

I thought Duttos posts had some substance tbh

 

[Sadfield]

Oh dear.

Which bits?

 

[terrym]

Oh dear.

Which bits?

Why not just chill?
Accept people have a different point of view to yours
So, have a beer or something.
Go for a walk perhaps.
Find something else to do.
In the end in the overall scheme of things it isn't worth it.
Trust me :thumb:

 

[Sadfield]

Totally chilled, it is possible to disagree with someone without getting irate, and even enjoy a debate. Isn't that the point of a forum?

Let's all ignore science and enjoy the misinformation.:thumb:

 

[dad_of_jon]

The bit dutto raised about boiling wort interested me. I only do small boils and i top up with chilled bottled water. So that would fit in with the fact that some people don't bother to aerate and don't have problems. Wherry which is a kit wouldn't require boiling of the wort. I say apart from the temp of the ferment the amount and condition of the yeast are the biggest culprits.

I have seen cans of wherry stored high up on the shelves where its quite warm in a certain store and often thought.... that's not the best way to keep the yeast happy. :-(

 

[Paydoogs]

Anyway, hey Mancer, my scotch ale kit stuck at 1020.

I pitched some additional gervin ale yeast.
Gave the whole wort a good stir but didn't go mental (even started to bubble again soon after).
Resurrected my water bath and made sure it stayed constant at 21C.

One week later....
Bingo, now just over 1010 :thumb:

 

[Clint]

...tis witchcraft........

 

[Sadfield]

Can't go for a chilled out walk as I have a boil going.

The bit dutto raised about boiling wort interested me. I only do small boils and i top up with chilled bottled water. So that would fit in with the fact that some people don't bother to aerate and don't have problems. Wherry which is a kit wouldn't require boiling of the wort. I say apart from the temp of the ferment the amount and condition of the yeast are the biggest culprits.

I have seen cans of wherry stored high up on the shelves where its quite warm in a certain store and often thought.... that's not the best way to keep the yeast happy. :-(

Nail hit squarely on head.

Oxygen is only needed for the growth phase, so as long as there is enough heathly yeast with the kit, dry yeast shouldn't need aeration, as it manufactured to not need it. However aeration is recommend as a way to get the yeast mixed in the wort.

From Fermentis

Does the wort need Oxygenation / aeration?
As the yeast is grown aerobically, the yeast is less sensitive on first pitch. Aeration is recommended to ensure full mixing of the wort and yeast.

Poor yeast health, insufficient yeast cells or inadequate mixing in wort can all lead to a longer lag phase and slow start to fermentation. The problem here is that yeast is flocculant and wants to clump together and sink to the bottom of the FV. Yeast also consumes sugars in wort in the order of simpliest tp complex, so it ends up a race against time after a slow start with a highly flocculant English yeast to get the job done before the yeast flocculates and impedes the conversion of the more complex sugars into alcohol and Co2. The kicker here is that sugars in wort inhibate flocculation, and so as fermentation progresses the more the yeast flocculates.

Fermentation temperature has an influence also, with yeast fermenting at warmer temperatures, but more critcal to yeast performance is stable temperature. I'll wager most stuck Wherry fermentations have no temperature control.

Yeast performance will also be affected by the fermentation environment. Conditions that are too warm will not impair fermentation and attenuation, but will affect beer flavor, generally creating more fusel alcohols, esters and phenols than desired. Conditions that are too cool will generally slow the fermentation, which may impact attenuation, but ultimately the beer should finish if the temperature is stable and all other yeast factors are being met. Fluctuating conditions, though, can definitely impact yeast performance, and cause them to stop before the beer is finished.

https://byo.com/body/item/1895-attenuation-advanced-brewing

And then we come to wort pH, in all grain brewing a wort pH of 5.0-5.2 is desired for good fermentation. I'm sceptical that when rehydrating kits that this is always achieved in areas with a highly alkaline water supply.

Here is an interesting thread regarding the importance of pH on yeast performance.

https://chemistry.stackexchange.com/questions/11160/why-does-ph-affect-fermentation


So in short, avoid stuck fermentations in Wherry (or any other beer) by:

1) Using sufficient fresh and healthy yeast.

2) Thoroughly mix your yeast and wort.

3) Control the fermentation temperature.

 

[Gunge]

So basically the Wherry yeast is crap and struggles in situations and conditions that others don't.

 

[AdeDunn]

One thing that puzzles me...
It's said that the wort should be aerated as the yeast needs oxygen and that (particularly during any boiling if done) oxygen is driven off and should be replaced with poring the wort from height,thrashing it up,air stone or whatever.
I understand "water" is H20....ie 2 of hydrogen and 1 of oxygen. ..so if the wort is low or oxygen depleted what exactly is left in the pan? Just the H?

The oxygen in H2O isn't free oxygen (O2) as it's molecularly bonded to the 2 hydrogen atoms. To free it you have to apply energy to the bonds to break them. Kinda like if you keep fish in water that doesn't contain any dissolved oxygen, they suffocate. Kinda like how plastic and fat are very similar on paper, but nothing like in reality.

 

[johnnyboy1965]

I really dont agree with the whole Woodfordes Wherry "stuck" syndrome.
It seems to be a default answer.
Has anybody contacted Woodfordes?
It doesnt matter anyway as the kits are made by Muntons in Nottingham (IIRC)
The yeast they supply is the same in all Woodfordes kits, but its only the Wherry that sticks.
Im not saying that every brewer who has had a Wherry stick is wrong....the statistics dont lie. In my early stages of HBing, I brewed 5 WW and not one of them "stuck".
I always enjoyed my WW HB and when I got a chance to drink a original WW in Norfolk, I thought that the kit was as close to the original as you could get.
JMHO