High FG - Stuck fermentation?

[mickc]

4 days ago I brewed an AG bitter recipe which had an OG of 1058 and a volume of 21 litres. Pitched in rehydrated Llaland London and kept it in my temperature controlled cupboard at 21 degrees. It had a really vigorous ferment which overflowed through the airlock and lasted a little over a day, but for the last 2 days nothing, gravity has been 1020 and no apparent movement through the airlock. I'd appreciate the thoughts of those with more experience.

 

[MrRook]

What was your actual recipe? What was your mash temperature and length?

 

[Brew_DD2]

That's a big Bitter! How are you measuring your FG?

 

[mickc]

What was your actual recipe? What was your mash temperature and length?

3.5kg MO, 1kg golden promise, 500gr brewing sugar, 80gr roasted malt, 20 litres, 67 degrees for an hour, 10 litres sparge. Boiled for 70 minutes and took gravity once cooled to 21 degrees.

 

[mickc]

That's a big Bitter! How are you measuring your FG?

I have a tap on the FV, just draw off enough to use a hydrometer.

That's a big Bitter! How are you measuring your FG?

I'm the first to admit I'm a numpty, there was a lot more grain than the recipe called for. I decided to bump it up by 500gr but ended up going 1kg over 'cos my memory isn't what it used to be!

 

[MrRook]

A lot of people are getting somewhat higher final gravity than they'd like with this yeast.

 

[Cwrw666]

4 days for a 1058 brew. Surely it's not finished yet.

 

[dmtaylor]

The Lalbrew London yeast is known to finish in 36-40 hours at an average apparent attenuation of 67%. My bet is the fermentation is complete, regardless of mash temperature, fermentation temperature, or anything else. Like many other English yeasts, this yeast strain has a difficult time fermenting maltotriose (a somewhat more complex malt sugar).

https://docs.google.com/spreadsheets/d/16XRUloO3WXqH9Ixsf5vx2DIKDmrEQJ36tLRBmmya7Jo/edit?usp=sharing

 

[mickc]

The Lalbrew London yeast is known to finish in 36-40 hours at an average apparent attenuation of 67%. My bet is the fermentation is complete, regardless of mash temperature, fermentation temperature, or anything else. Like many other English yeasts, this yeast strain has a difficult time fermenting maltotriose (a somewhat more complex malt sugar).

https://docs.google.com/spreadsheets/d/16XRUloO3WXqH9Ixsf5vx2DIKDmrEQJ36tLRBmmya7Jo/edit?usp=sharing

OK, thanks for that.