Stuck fermentation?

[Nottsbeer]

Hi, I'm a few days into brewing a bitter. OG was 1.043 and estimated FG is 1.010. Fermentation seems to have stopped at 1.020 (tracked using an ispindle and confirmed using hydrometer). I'm thinking of upping the temp (currently at 19.5) to 21oC. Should I also give the beer a stir? Never had this issue before so but puzzled. Mash was at 68oC for 90 mins and yeast took off like a rocket. It's been constant at 1.020 for a couple of days. Cheers.

 

[Agentgonzo]

Which yeast did you use? Some yeast have weird characteristics.

> Should I also give the beer a stir?

General advice is if you can stir it without taking the airlock/lid off, then go for it. Otherwise it's too much risk (oxidisation).

 

[Clint]

A few days in...leave it and check this time next week.

 

[Nottsbeer]

Which yeast did you use? Some yeast have weird characteristics.

> Should I also give the beer a stir?

General advice is if you can stir it without taking the airlock/lid off, then go for it. Otherwise it's too much risk (oxidisation).

Cheers. I used CML The Firm (first time using it). Yes, I'm not too keen on opening the fermenter.

 

[Agentgonzo]

Apparently, CML The Firm is just repackaged Windsor yeast ('The Firm' is slang for the royal family, hence Windsor, and people who've brewed with it seem to say it behaves the same, so it's a fairly good guess). There seem to be lots of posts about Windsor and stuck fermentation if you do a google search. I'd do a bit of googling for that and see what a variety of forum posts suggest.

 

[Nottsbeer]

Apparently, CML The Firm is just repackaged Windsor yeast ('The Firm' is slang for the royal family, hence Windsor, and people who've brewed with it seem to say it behaves the same, so it's a fairly good guess). There seem to be lots of posts about Windsor and stuck fermentation if you do a google search. I'd do a bit of googling for that and see what a variety of forum posts suggest.

Thx for your info. Seems this is a common issue. Will chuck in some other yeast once I get some to bring it down the last 10 points.

 

[aw72]

Hi, I have used Windsor yeast and had similar experience. It is a low attenuating yeast. I had around 65% attenuation, which is quite common. With your O.G of 1043 I would expect it to be finished at around 1015?

 

[Sandimas]

It is a low attenuating yeast. I had around 65% attenuation, which is quite common.

I got 65% with it too, quite disappointed with it to be honest, wouldnt use it again.

 

[Nottsbeer]

Hi, I have used Windsor yeast and had similar experience. It is a low attenuating yeast. I had around 65% attenuation, which is quite common. With your O.G of 1043 I would expect it to be finished at around 1015?

It's definitely not budging anymore. Think day 3 now of no movement. I have maybe 1/4 of a pack of Four yeast in the fridge and some Premium Gold. I may chuck in the Four and see if it shifts a bit more

 

[YeastFace]

Ignore - completely wrong thread.

 

[The-Engineer-That-Brews]

It seems the attenuation of a yeast can change according to how you do the mash...

My most recent brew (GH ESB) started at 1.050 and is down to 1.008 on the hydrometer so an apparent attenuation of over 83% - using WY1187 Ringwood, which is meant to have a range of 68-72%.

I suspect this is because I did a step mash designed to give a good slug of beta amylase activity and break down the complex sugars into stuff the yeast can eat?

 

[peebee]

You are using a low attenuating yeast (they are never called that for some reason - "medium attenuator" ). A "low attenuating" yeast will be fairly averse to normally fermentable dextrin ("maltotriose"), and you mashed fairly high at 68°C which can increase the dextrin content of the wort. It is NOT a fault of the yeast! I use this "feature" to purposely create beers that finish with a high gravity. Dextrin isn't particularly sweet so no issue with the beer being too sweet.

Add half a packet of something a bit more attenuating (like US-05, dreadfully boring yeast in my opinion, but, hey ...), don't stir, there's no need but be warned it might take a while to "engage" (I mis-calculated a mash, finished at 1.027, and it took 4-5 days for the replacement to take over which fermented it down to 1.012 - I was originally aiming for 1.018). Ignore the clammer to not have the likes of "Windsor", "The Firm", "S-33", etc. unavailable, they just want beer reduced to a single "style" that suits them! Boring ...

 

[Nottsbeer]

You are using a low attenuating yeast (they are never called that for some reason - "medium attenuator" ). A "low attenuating" yeast will be fairly averse to normally fermentable dextrin ("maltotriose"), and you mashed fairly high at 68°C which can increase the dextrin content of the wort. It is NOT a fault of the yeast! I use this "feature" to purposely create beers that finish with a high gravity. Dextrin isn't particularly sweet so no issue with the beer being too sweet.

Add half a packet of something a bit more attenuating (like US-05, dreadfully boring yeast in my opinion, but, hey ...), don't stir, there's no need but be warned it might take a while to "engage" (I mis-calculated a mash, finished at 1.027, and it took 4-5 days for the replacement to take over which fermented it down to 1.012 - I was originally aiming for 1.018). Ignore the clammer to not have the likes of "Windsor", "The Firm", "S-33", etc. unavailable, they just want beer reduced to a single "style" that suits them! Boring ...

Maybe silly question - if I left it alone and primed in the bottle as normal with sugar, would it condition as normal or is there a danger of over carbonation if the yeast kicks in again? I presume the yeast would only eat the priming sugar as it's used everything else it could. Don't want to end up with bottle bombs.

 

[peebee]

Difficult to say. I use the term "averse" because I find these yeasts are inclined to perhaps have a go at the "difficult" stuff now and again and I have had kegs get well over-carbonated after a few months (using S-33). But, provided with a readily fermentable sugar (primings) it should have a go at that with no hesitation.

I don't bottle and have available means of slowly relieving over-pressure in kegs (slowly relieve pressure because excess press in solution takes time to vent off). So, I'm not the best person to ask about the potential of over-carbonated bottles.