Author Topic: Lower than expended attenuation  (Read 1141 times)

Offline BrewBama

  • Brewmaster General
  • *******
  • Posts: 2539
Lower than expended attenuation
« on: February 19, 2017, 04:53:51 AM »
I recently brewed an ESB with 8 lb Golden Promise (89%) and 1 lb Double Roasted Crystal (11%) mashed at 153*F.  Though I've read crystal malts can be used up to 20%, I rarely use more than 10%. I used 1% over my 'personal crystal limit' but I didn't think much about it.

I used S-33 yeast with this beer in an effort to brew an authentic English Ale. I pitched at 62*F and had a strong activity within a few hrs.  As ferm activity began to slow after a cpl days I began ramping up the temp to 70*F to coax it to finish. Per the yeast spec sheet optimum temp is between 59-68*F.

My OG was 1.054 which was spot on my prediction and I expected a 1.016 FG (70%) but even after increasing temp the best I could get is 1.020 (63%).  It's only 4 points and 4.5 vs 5% ABV so I threw in the towel accepting my 7% less attenuation and kegged it today. This is my Daytona party beer and I still have to cold crash, clear, and carb it this week.

I checked the thermometer I used against another and found them to be within 2*F so I feel OK there.

What do you think caused my 7% loss in attenuation?
“From man’s sweat and God’s love, beer came into the world.” — St. Arnold

Brewed in the Tennessee Valley. Rocket City — Huntsville AL

Offline HoosierBrew

  • I must live here
  • **********
  • Posts: 13030
  • Indianapolis,IN
Re: Lower than expended attenuation
« Reply #1 on: February 19, 2017, 05:24:37 AM »
I recently brewed an ESB with 8 lb Golden Promise (89%) and 1 lb Double Roasted Crystal (11%) mashed at 153*F.  Though I've read crystal malts can be used up to 20%, I rarely use more than 10%. I used 1% over my 'personal crystal limit' but I didn't think much about it.

I used S-33 yeast with this beer in an effort to brew an authentic English Ale. I pitched at 62*F and had a strong activity within a few hrs.  As ferm activity began to slow after a cpl days I began ramping up the temp to 70*F to coax it to finish. Per the yeast spec sheet optimum temp is between 59-68*F.

My OG was 1.054 which was spot on my prediction and I expected a 1.016 FG (70%) but even after increasing temp the best I could get is 1.020 (63%).  It's only 4 points and 4.5 vs 5% ABV so I threw in the towel accepting my 7% less attenuation and kegged it today. This is my Daytona party beer and I still have to cold crash, clear, and carb it this week.

I checked the thermometer I used against another and found them to be within 2*F so I feel OK there.

What do you think caused my 7% loss in attenuation?


What temp did you mash at, out of curiosity? Think your thermometer is reading accurately? I've never used the double roasted crystal, but I'm betting it's even less fermentable than the paler crystals. I usually mash a few degrees cooler when I use a high amoumt of crystal, to finish low enough. My $0.02  .

 
Jon H.

Offline Frankenbrew

  • Brewmaster
  • *****
  • Posts: 687
  • South Shore Brew Club, SE Massachusetts
Re: Lower than expended attenuation
« Reply #2 on: February 19, 2017, 02:04:19 PM »
 Is S-33 like Windsor in that it doesn't ferment maltotriose? It sounds as like what often happens with Windsor.
Frank C.

And thereof comes the proverb: 'Blessing of your
heart, you brew good ale.'

Offline BrewBama

  • Brewmaster General
  • *******
  • Posts: 2539
Lower than expended attenuation
« Reply #3 on: February 19, 2017, 02:12:15 PM »


What temp did you mash at, out of curiosity? Think your thermometer is reading accurately? I've never used the double roasted crystal, but I'm betting it's even less fermentable than the paler crystals. I usually mash a few degrees cooler when I use a high amoumt of crystal, to finish low enough. My $0.02  .

153*F (over shot my 152*F target but I'm ok with that). I checked the therm I used against another. They were within 2*F. I also check my hydrometer. It floats at 1.000 with water.

Is S-33 like Windsor in that it doesn't ferment maltotriose? It sounds as like what often happens with Windsor.

Yes. I thought I accounted for that by expecting only 70%.

I am chalking this up to a natural product doing what nature pleases despite what I expected. If the results are otherwise good, I may brew this again using 3% less crystal, lower mash temp to 150*, and when/if it stalls I think I'll gently stir the yeast back into suspension to see it I can get that last 7%.


Sent from my iPad using Tapatalk
« Last Edit: February 19, 2017, 02:28:22 PM by BrewBama »
“From man’s sweat and God’s love, beer came into the world.” — St. Arnold

Brewed in the Tennessee Valley. Rocket City — Huntsville AL