Stuck Fermentation

[greg]

I've recently moved on to partial and full mashes. In conjunction with this I have also used liquid yeasts an awful lot more. Everything seemed to be going quite well until recently.

I made a London Pride Clone with a Wyeast and the FG stuck around the 20's, luckily I had another fermenter on the go and I pitched the suspect SG onto that yeast cake. It got down to a lower FG, but not as low as the other.

Then I made a lager with a Wyeast but this one also stuck, I tried every way I could to get the fermentation going again, including pitching another yeast and dextrose, but to no avail. :angry:

I made the same beer with a dried lager yeast and alls well.

I always make up a starter of 1.5-2ltrs which I pitch at the relevant tempreature. I aerate my wort using hose and nozzle, rack at half SG and try and keep a stable tempreature.

Whats going on what am I doing wrong? I've read that liquid yeast requires greater aeration than dried, how do I acheive this.

Any help would be greatfully appreciated as I'm a little reluctant to use liquid yeast again.

greg

 

[kook]

What kind of gravity are you trying to get down to? And how long are you leaving it for ?

It sounds like you're giving plenty of aeration, and with a 1-2L starter I cant see why you would have these problems. Maybe avoid racking at half gravity, and wait till its almost finished before you rack it ?

Also, why did you pitch dextrose in the lager to rouse the yeast?? If anything that would stop the yeast from breaking down the maltose and work at breaking down the dextrose.

I've had WYeast (scottish ale) bring a beer down from 1091 to 1021 with only a 750ml starter, and the only aeration was dropping the beer from the boiler to the fermenter.

 

[Snow]

At the risk of starting a bit of biffo, I have heard, and read, that this is more of a common problem with Wyeast than most people are aware. In particular, I have heard of many stuck fermentations with Wyeast lager yeasts. Of course this could all be bollocks ad these guys just don't know how to use the yeast, but it may be worthwhile experimenting with White Labs for comparison's sake.

- Snow.

 

[Gout]

I have also heard that a lot, I must say i know very little and have never used them, but i am wanting to try liquid yeasts, and hence i have been looking through as many fourums etc as i can and the Lager yeast in the Wyeast has been names a lot in this regard. I would love to know more as i want to use a lager yeast as my first brew (make a prem lager)

Regards
Ben

 

[greg]

Thanks for the help and advice. I have also heard several suggestions about Wyeast, however at this stage of my brewing with liquid yeast I am more inclined to belive that the problem lies with my technique. I will stop racking at half SG to see whether this makes a difference.

The reason I added dextrose was pure fustration and lack of knowledge, two things tht really shouldn't be combined

Once again thanks for the input

greg

 

[greg]

Sorry Kook,

I expected to get an FG of about 1006 using the calculator and my Sg was 1048.

 

[johnno]

At the risk of starting a bit of biffo, I have heard, and read, that this is more of a common problem with Wyeast than most people are aware. In particular, I have heard of many stuck fermentations with Wyeast lager yeasts. Of course this could all be bollocks ad these guys just don't know how to use the yeast, but it may be worthwhile experimenting with White Labs for comparison's sake.

- Snow.

Hi all,
Whats the experience with Wyeast and stuck ferments. My oatmeal stout that I put on Saturday using a Wyeast 1084 has sudennly stopped at 1030 today. OG was 1060. This is the second stuck ferment i have had with a Wyeast. The first was a porter using the 1028. That stuck at about 1020 and by constant shaking came down a bit more. My starters are alway over a litre. The 1084 was about 1.3 litres and I always fill up with the hose and I'm sure its areating enough as Im getting massive foaming. This one was strating to work about 5 hours after pitching. Within 24 hours it was going really strong. I have had to get another starter going tonight to pitch more. I will also try bringing the temp up by heating it a bit.Temp has been at a constant 18-20 c.
Whitelabs dont seem to be as easily available in Melb.

cheers

 

[Snow]

Johnno, I must admit I've never had a stuck ferment with Wyeast before. I've used the 1084 a fair bit and had no problems. I always put in a teaspoon of yeast nutrient in the boil and aerate like buggery. I try to have at least 1.5L starter for each batch.

Cheers - Snow

 

[THE DRUNK ARAB]

greg, the yeast u are using from Wyeast will have a certain attenuation rate. For example if a yeast has 75% attenuation and your beer had an OG of 1048 you would expect a typical final gravity of 1012 (100% attenuation would give FG of 1000). What you are aiming for is 87% attenuation to get your beer down to 1006 and I don't believe any of the Wyeast yeasts attenuate down that far. :huh:

Find out the attenuation rate of the yeast you are using and then you know what FG you will be aiming for.

And definately don't rack your beer until fermentation is complete as yeast still has a job to do in cleaning up some components of your beer.

For what it is worth I am yet to have a problem with Wyeast and stuck fermentation.

Hope this is of some help.

C&B
TDA

 

[user 384]

You might also want to look at the composition of your wort.

Extract and Partials:
Different extracts have different degrees of fermentability. These problems are in large part caused by low free amino nitrogen (FAN) levels (not a problem when using grain). Lager yeast have been reported as particularly sensitive to FAN levels. Also different extracts have different compositions, some are all malt and some are cut with other cheaper sugars that can negatively impact on your yeast ability to ferment the wort.

All-grain:
Higher mash temps will produce a more dextrinous wort which will be less fermentable. Using large quantities of crytal malts will also leave a large amount of unfermentable sugars.

So even if the yeast is capable of 75% attenuation, it will only be able to work on that component of your wort that is made up of fermentable sugars.

Like TDA, I've never had a problem with Wyeast.

Cheers
MAH

 

[Wreck]

Greg,

You also mention racking at half SG. There's been a bit of discussion on here about when to rack. I think the general consensus was to let it go all the way in primary, and then rack. Main reason being the risk of stuck ferments.

Wreck.

 

[Wreck]

Sorry TDA, you got in before me on the racking point. Amazing how quick replies can appear on here. B)

 

[johnno]

Well this one has me stumped in my short brewing career. Stopped at 1030 a week ago. Tried another starter. Nothing. Tried a Safale. Got down to 1026.
My hydrometer is fine as its reading Melb water at 1000.
Here is the recipe.
3.00 Kilos Pale DME
1 kilo base malt. Marris Otter
.400 Kilo Flaked Oats
.400 kilo Crystal
.300 kilo Choc malt
.200 kilo Black malt
.150 Kilo Roasted Barley
Wyeast 1084 Irish Ale yeast
EKG for bittering
Mahed all the grain at 67 c for an hour.
This was fermenting really strongly for the first 3 days. Nearly came out of the airlock.
Funny thing is I racked to secondary tonight and it had the biggest, thickest, meanest yeast cake I have ever had in a brew. Could it be finished?
Either way it will not escape. I will drink it somehow.

cheers

 

[deebee]

Johnno

What was the OG?