Author Topic: lack of attenuation...here we go again...  (Read 1635 times)

Offline goschman

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lack of attenuation...here we go again...
« on: November 18, 2015, 09:34:36 PM »
Have a batch that started at 1.050 and is currently at 1.020 on Day 12. I pitched 3 day old harvested K97 slurry using Mr Malty calculator. Fermentation took off quickly, was quite vigorous for a few days and then I ramped the temp up to about 70F once fermentation slowed. After a couple of days, I let it naturally fall to about 62F.

I have roused the settled yeast, pitched another packet of yeast, & raised the temp to see no signs of fermentation 24 hours later. Does it take longer to get going since less sugar is left in the wort?

Is it likely that I don't have a very fermentable wort and that it is just done? I am not sure how that is possible but I am a little clueless here. Been a long time since I have had any problem like this...
« Last Edit: November 18, 2015, 09:36:45 PM by goschman »
On Tap/Bottled: Haze for Daze IPA, G Pils, Maibock, Watermelon Cider         

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Offline Wort-H.O.G.

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Re: lack of attenuation...here we go again...
« Reply #1 on: November 18, 2015, 09:36:40 PM »
Have a batch that started at 1.050 and is currently at 1.020 on Day 12. I pitched 3 day old harvested K97 slurry using Mr Malty calculator. Fermentation took off quickly, was quite vigorous for a few days and then I ramped the temp up to about 70F once fermentation slowed. After a couple of days, I let it naturally fall to about 62F.

I have roused the settled yeast, pitched another packet of yeast, & raised the temp to see no signs of fermentation 24 hours later. Does it take longer to get going since less sugar is left in the wort?

Is it likely that I don't have a very fermentable wort and that it is just done?

details...details! what was your grist and mash temp? check PH?
Ken- Chagrin Falls, OH
CPT, U.S.Army
https://www.facebook.com/pages/Harveys-Brewhaus/405092862905115

http://braukaiser.com/wiki/index.php?title=The_Science_of_Mashing

Serving:        In Process:
Vienna IPA          O'Fest
Dort
Mead                 
Cider                         
Ger'merican Blonde
Amber Ale
Next:
Ger Pils
O'Fest

Offline goschman

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Re: lack of attenuation...here we go again...
« Reply #2 on: November 18, 2015, 09:38:19 PM »
85% munich 6L
10% flaked oats
5% carafa I

152F mash rest for 60 minutes. Mash pH 5.5. 70% brewhouse efficiency. Not sure what current pH is

pitched about 100 mL of 3 day old harvested yeast slurry that had attenuated prior batch from 1.052 to 1.014
« Last Edit: November 18, 2015, 09:40:25 PM by goschman »
On Tap/Bottled: Haze for Daze IPA, G Pils, Maibock, Watermelon Cider         

Fermenting: Kolsch
Up Next: Summer Ale, Gose

Offline dilluh98

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Re: lack of attenuation...here we go again...
« Reply #3 on: November 18, 2015, 09:40:13 PM »
Hydrometer or refractometer that far off? Seems unlikely... 12 days should be plenty for that beer.

Offline goschman

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Re: lack of attenuation...here we go again...
« Reply #4 on: November 18, 2015, 09:40:56 PM »
Hydrometer or refractometer that far off? Seems unlikely... 12 days should be plenty for that beer.

Same hydrometer I always use. Calibrated as reading 1 point too high. Sample didn't taste as sweet as I would expect
On Tap/Bottled: Haze for Daze IPA, G Pils, Maibock, Watermelon Cider         

Fermenting: Kolsch
Up Next: Summer Ale, Gose

Offline Wort-H.O.G.

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Re: lack of attenuation...here we go again...
« Reply #5 on: November 18, 2015, 09:42:47 PM »
85% munich 6L
10% flaked oats
5% carafa I

152F mash rest for 60 minutes. Mash pH 5.5. 70% brewhouse efficiency. Not sure what current pH is

pitched about 100 mL of 3 day old harvested yeast slurry that had attenuated prior batch from 1.052 to 1.014

ale? yeah im guessing something possible went wrong in the mash. yeast amount and health would seem plenty.
Ken- Chagrin Falls, OH
CPT, U.S.Army
https://www.facebook.com/pages/Harveys-Brewhaus/405092862905115

http://braukaiser.com/wiki/index.php?title=The_Science_of_Mashing

Serving:        In Process:
Vienna IPA          O'Fest
Dort
Mead                 
Cider                         
Ger'merican Blonde
Amber Ale
Next:
Ger Pils
O'Fest

Offline goschman

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Re: lack of attenuation...here we go again...
« Reply #6 on: November 18, 2015, 09:43:59 PM »
85% munich 6L
10% flaked oats
5% carafa I

152F mash rest for 60 minutes. Mash pH 5.5. 70% brewhouse efficiency. Not sure what current pH is

pitched about 100 mL of 3 day old harvested yeast slurry that had attenuated prior batch from 1.052 to 1.014

ale? yeah im guessing something possible went wrong in the mash. yeast amount and health would seem plenty.

Yes ale. I will have to go back and take a look at my notes to see if anything was off from my normal process. I am hoping that somehow it starts back up again but not much more I can do.
On Tap/Bottled: Haze for Daze IPA, G Pils, Maibock, Watermelon Cider         

Fermenting: Kolsch
Up Next: Summer Ale, Gose

Offline Wort-H.O.G.

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Re: lack of attenuation...here we go again...
« Reply #7 on: November 18, 2015, 09:51:56 PM »
85% munich 6L
10% flaked oats
5% carafa I

152F mash rest for 60 minutes. Mash pH 5.5. 70% brewhouse efficiency. Not sure what current pH is

pitched about 100 mL of 3 day old harvested yeast slurry that had attenuated prior batch from 1.052 to 1.014

ale? yeah im guessing something possible went wrong in the mash. yeast amount and health would seem plenty.

Yes ale. I will have to go back and take a look at my notes to see if anything was off from my normal process. I am hoping that somehow it starts back up again but not much more I can do.

is 70% mash efficiency your norm? k-97 for this as described should have finished 1.012-1.014. i would say its done and that's it. if you're confident in both mash PH and temp, the other thing would be the slurry.....more dead cells than healthy cells-but you will never figure that out.
Ken- Chagrin Falls, OH
CPT, U.S.Army
https://www.facebook.com/pages/Harveys-Brewhaus/405092862905115

http://braukaiser.com/wiki/index.php?title=The_Science_of_Mashing

Serving:        In Process:
Vienna IPA          O'Fest
Dort
Mead                 
Cider                         
Ger'merican Blonde
Amber Ale
Next:
Ger Pils
O'Fest

Offline goschman

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Re: lack of attenuation...here we go again...
« Reply #8 on: November 18, 2015, 09:55:19 PM »
70% brewhouse efficiency is pretty average for me.

Maybe the thermometer needs to be checked/calibrated...

Well looks like I will have a sweet session beer around. Hopefully it's not too bad...
On Tap/Bottled: Haze for Daze IPA, G Pils, Maibock, Watermelon Cider         

Fermenting: Kolsch
Up Next: Summer Ale, Gose

Offline Wort-H.O.G.

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Re: lack of attenuation...here we go again...
« Reply #9 on: November 18, 2015, 09:57:52 PM »
70% brewhouse efficiency is pretty average for me.

Maybe the thermometer needs to be checked/calibrated...

Well looks like I will have a sweet session beer around. Hopefully it's not too bad...

was 5.5PH a target or actual reading you got? not sure if you use PH  meter or not.
Ken- Chagrin Falls, OH
CPT, U.S.Army
https://www.facebook.com/pages/Harveys-Brewhaus/405092862905115

http://braukaiser.com/wiki/index.php?title=The_Science_of_Mashing

Serving:        In Process:
Vienna IPA          O'Fest
Dort
Mead                 
Cider                         
Ger'merican Blonde
Amber Ale
Next:
Ger Pils
O'Fest

Offline goschman

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Re: lack of attenuation...here we go again...
« Reply #10 on: November 18, 2015, 10:02:08 PM »
70% brewhouse efficiency is pretty average for me.

Maybe the thermometer needs to be checked/calibrated...

Well looks like I will have a sweet session beer around. Hopefully it's not too bad...

was 5.5PH a target or actual reading you got? not sure if you use PH  meter or not.

target pH. I use bru'n water along with my Wards Lab water analysis to make adjustments. It has worked well up to this point but obviously I may be off there as well. pH meter is on the list of things to get...
On Tap/Bottled: Haze for Daze IPA, G Pils, Maibock, Watermelon Cider         

Fermenting: Kolsch
Up Next: Summer Ale, Gose

Offline dilluh98

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Re: lack of attenuation...here we go again...
« Reply #11 on: November 18, 2015, 10:06:39 PM »
Anything different about your mash thickness? Kind of grasping at straws here but I have seen some shifts in pH going from a batch sparge to no sparge with same grist and salt/acid additions - not drastic, but there was a difference. But this doesn't make sense as your efficiency didn't take a major hit... hmmm. I'm stumped.

Online dmtaylor

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Re: lack of attenuation...here we go again...
« Reply #12 on: November 18, 2015, 10:08:51 PM »
Might just be a mash thermometer calibration thing.  Easy to check.  Boil some water and see what it reads.  Don't forget to adjust boil temperature based on your own elevation on the planet Earth -- boiling point is 212 F only right at sea level.
Dave

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Offline dilluh98

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Re: lack of attenuation...here we go again...
« Reply #13 on: November 18, 2015, 10:15:40 PM »
Might just be a mash thermometer calibration thing.  Easy to check.  Boil some water and see what it reads.  Don't forget to adjust boil temperature based on your own elevation on the planet Earth -- boiling point is 212 F only right at sea level.

It's always good to calibrate your equipment properly but I've never had a moderate gravity beer finish at 1.020, even when mashing close to 160 F. I guess if a thermometer is waaay off...

Offline goschman

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Re: lack of attenuation...here we go again...
« Reply #14 on: November 18, 2015, 10:19:11 PM »
I will check it. I calibrated it right when I got it but that was a year ago. It would have to have changed considerably and likely be reading at least 8F to low. Looks like boiling temp at my location should be about 202F
« Last Edit: November 18, 2015, 10:21:54 PM by goschman »
On Tap/Bottled: Haze for Daze IPA, G Pils, Maibock, Watermelon Cider         

Fermenting: Kolsch
Up Next: Summer Ale, Gose