Fermentation issues

[Martybhoy]

Not for the first time, I am struggling to reach my FG target. But my current brew is the poorest fermentation I've had for a long while (9 points off target). My recipe is below, with some procedure notes. If there's something not quite right, or that I can improve, I'd appreciate some advice -

American Amber Ale (10ltr BIAB)
1.50kg Maris Otter
1.00kg Munich
0.125kg Crystal
0.125kg Pale Crystal
0.100kg Special B

Mash water treated with
2.78g gypsum
0.22g chalk

Mashed at 68° for 75 mins in 13ltrs.
Mashed out to 75°.
Sparged with 2ltrs @75°.

Boil water treated with
0.58g table salt
1.45g Epsom salts
1.78g gypsum

The water treatment was based on this site's calculator and my own water report.

Boiled for 75 mins with several hop additions (assuming the hops aren't an issue, I won't list them).

Cooled to 19°. Then transferred from height to FV - 9.5ltrs.

OG - 1.064 (on target)

Aerated by vigorous stirring (my new aeration kit wouldn't work). Then I pitched 124bn cells of WLP001.

Fermented at 20° in brewfridge.


Over 2 weeks later, I'm stuck at 1.025, and my target is 1.016. I have repitched a sachet of WLP001 at high krausen but to no avail. I'm not bothered about how to fix this particular brew, but more on what I could do in future to ensure a good fermentation.

My sanitation (I think) is not an issue as I'm pretty thorough. Should I pitch at a higher rate? Also, next brew I'll be using an aerator for the first time, so hopefully this will help.

Any help much appreciated.

 

[simon12]

Not sure but I would 1st check the fridge temp is calibrated correctly and if all is OK there maybe try a reliable dried yeast (nottingham or US05) to rule that out. Also mash a bit lower and double check that temp.

 

[Dutto]

You have virtually self diagnosed with the word "stuck" ...

... but DO NOT dump this particular brew.

Personally, in this situation I would open up the FV, beat it as if it owed me money (to quote another Thread) to aerate it, sling in a packet of Wilco Ale Yeast, button up the FV and leave it at about 20 degrees for another week before checking the SG again.

IF you haven't introduced an infection, IF the brew starts fermenting again and IF there are no bad smells coming from the FV then you should easily reach the required FG. (Personally, I consider 1.016 to be very high!)

I would then leave it for another week to give the yeast time to tidy up the brew and bottle normally.

Hope this helps.
:thumb:

 

[The Idiot]

First off, I wouldn't put any more yeast into it. If you've put two lots of different yeast in then that should be fine.

20 degrees C is right at the bottom of the advised fermentation temperature for WLP001. The drop from 1.064 to around 1.030 will happen fast, then the yeast slows down. It's not just eating sugar and pooping alcohol; it's also having a bit of a clear-up and making good beer things happen. In my opinion and based on around 40 odd years of breewing, I've never seen a fermantation properly finish in two weeks. Some will tell you otherwise, but I'll bet a whole load of something that if you leave your beer go another week or two it'll be where you want it, and a whole lot better than if you chuck any more yeast at it.

You also say you pitched a second pack of WLP001 at high krausen. That would have been a few days after fermentation started. Is that what you mean?

It'll ferment out cool but it'll take its time. Did you make a starter with the yeast?

There are many systems, often flawed, that people will tell you with some insistence are the only way to properly brew; the truth is that patience and the ability to resist tinkering and messing will serve you much better than their perceived wisdom. Have a beer and wait for it to do its thing!

 

[Martybhoy]

First off, I wouldn't put any more yeast into it. If you've put two lots of different yeast in then that should be fine.

20 degrees C is right at the bottom of the advised fermentation temperature for WLP001. The drop from 1.064 to around 1.030 will happen fast, then the yeast slows down. It's not just eating sugar and pooping alcohol; it's also having a bit of a clear-up and making good beer things happen. In my opinion and based on around 40 odd years of breewing, I've never seen a fermantation properly finish in two weeks. Some will tell you otherwise, but I'll bet a whole load of something that if you leave your beer go another week or two it'll be where you want it, and a whole lot better than if you chuck any more yeast at it.

You also say you pitched a second pack of WLP001 at high krausen. That would have been a few days after fermentation started. Is that what you mean?

It'll ferment out cool but it'll take its time. Did you make a starter with the yeast?

There are many systems, often flawed, that people will tell you with some insistence are the only way to properly brew; the truth is that patience and the ability to resist tinkering and messing will serve you much better than their perceived wisdom. Have a beer and wait for it to do its thing!

I repitched when the starter was at high krausen, so that the yeast was highly active at the point I introduced it to the wort.



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[The Idiot]

I repitched when the starter was at high krausen, so that the yeast was highly active at the point I introduced it to the wort.

Right, I see. Stop pitching and let it do it's thing. If you've got a way of keeping the temperature at around 21-22 degrees C it would be good, but otherwise just be patient.

I'd expect to see an FG of around 1.020 to 1.015 given the percentage of Crystal and Special B.

 

[Martybhoy]

Is there anything I could do differently?

This was also my first brew where I milled my own grain. But, as I hit my OG, I don't think this would make any difference?

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[dan125]

Could it just be that a relatively high amount of crystal malts (12%) combined with a relatively high mash temp, have left you with a high FG?
I think it should be done after 2 weeks, especially as you pitched a good amount of yeast for a 9.5L brew.
They talked about a simple test for a stuck brew on an Experimental Brewing podcast I listened to recently - annoyingly I can't remember which one or the details, but I think it involved trying to use a small amount of the 'stuck' beer to make a starter with some dry yeast, to see if would ferment - if it doesn't your at the FG for that particular beer - I might have this wrong though.

 

[Martybhoy]

I've heard of that method also, but don't have dry yeast to try it with.

I have came down 3 points since repitching, so it is (slowly working).

I did think that maybe I'd exhausted all the fermentables, but 9 points off is too much. I'm now 6 points off, and counting (hopefully), and still have the sugar addition to try.

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[dan125]

Is there anything I could do differently?

Also worth thinking about increasing the brewfridge temp a little after the initial vigorous fermentation to help the yeast finish up.
I tend to start a degree or so below the recomended min for the yeast to allow for a bit of a higher temp in the FV, and start rising slowly after the krausen drops.

 

[Martybhoy]

Top end of WLP001 is 22°, which I'm currently at. Do you think I could safely go any higher, given that the main fermentation is done?

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[dan125]

I've heard of that method also, but don't have dry yeast to try it with.

I have came down 3 points since repitching, so it is (slowly working).

I did think that maybe I'd exhausted all the fermentables, but 9 points off is too much. I'm now 6 points off, and counting (hopefully), and still have the sugar addition to try.

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If its coming down then I guess you just have to be patient

 

[dan125]

Top end of WLP001 is 22°, which I'm currently at. Do you think I could safely go any higher, given that the main fermentation is done?

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#

I don't think you'd cause any off flavours at this stage but not sure it will help much if you're already at 22