Author Topic: Big beer OG Misses  (Read 688 times)

Offline yso191

  • Senior Brewmaster
  • ******
  • Posts: 1785
  • Yakima, WA
    • View Profile
Big beer OG Misses
« on: August 06, 2015, 12:29:41 AM »
I need to figure out what is going on.  I hit my numbers consistently with average gravity beers.  But every time I attempt a big beer I miss my numbers - sometimes by a lot. 

Today I brewed a RIS which was supposed to be 1.092 OG.  I took a pre-boil gravity and it showed 10 points lower than predicted so I added all the DME I had (about 13 oz.).  Even with that the OG is sitting at 1.077!

The grain crush was good.  Brun'water predicted a pH of 5.5.  My temperature held steady in the mash at ~155*.  It was an hour mash.  I planned a 90 minute mash but was running short on time so I kept it to an hour. 

I'm at a loss.  Any ideas?

The good news is that even when I miss my OG the beer still tastes good.  :)
« Last Edit: August 06, 2015, 12:32:27 AM by yso191 »
Steve
All Hands Brewing
BJCP #D1667

Offline HoosierBrew

  • Global Moderator
  • I must live here
  • *****
  • Posts: 13030
  • Indianapolis,IN
    • View Profile
Re: Big beer OG Misses
« Reply #1 on: August 06, 2015, 12:37:10 AM »
Was your final volume a little higher than expected ?  The DME should have made up most of that deficit, assuming 5 gallons. Could your FG reading have been stratified? I know it's easy to get a stratified reading after cooling to pitch temps.
Jon H.

Offline yso191

  • Senior Brewmaster
  • ******
  • Posts: 1785
  • Yakima, WA
    • View Profile
Re: Big beer OG Misses
« Reply #2 on: August 06, 2015, 01:16:26 AM »
I take the sample from the hoses that go from the BK to the fermenter.  So it has a lot of trub in it.  The wort is not yet to pitching temp.  I may take another sample once it gets there.
Steve
All Hands Brewing
BJCP #D1667

Offline a10t2

  • Official Poobah of No Life.
  • *
  • Posts: 4450
  • Ask me why I don't like Chico!
    • View Profile
    • SeanTerrill.com
Re: Big beer OG Misses
« Reply #3 on: August 06, 2015, 01:21:22 AM »
What was the mash efficiency? Are you compensating for the loss in efficiency on bigger beers?

For a beer that big I would only be expecting ~68% lauter efficiency on my system.

The next thing I'd try would be measuring pH to verify the calculations.
Sent from my Microsoft Bob

Beer is like porn. You can buy it, but it's more fun to make your own.
Refractometer Calculator | Batch Sparging Calculator | Two Mile Brewing Co.

Offline hopfenundmalz

  • Global Moderator
  • I must live here
  • *****
  • Posts: 8877
  • Milford, MI
    • View Profile
Re: Big beer OG Misses
« Reply #4 on: August 06, 2015, 01:27:41 AM »
My efficiency goes down with really big beers as one would expect.

The one I made that was at 1.115, it was a batch sparge, I ran some 1.040ish wort into a 10 gallon kettle I have, then boiled it hard until it was over target, added into the main batch. No small beer on that batch.
Jeff Rankert
Ann Arbor Brewers Guild
AHA Governing Committee
BJCP National
Home-brewing, not just a hobby, it is a lifestyle!

Offline yso191

  • Senior Brewmaster
  • ******
  • Posts: 1785
  • Yakima, WA
    • View Profile
Re: Big beer OG Misses
« Reply #5 on: August 06, 2015, 01:52:01 AM »
My efficiency goes down with really big beers as one would expect.

The one I made that was at 1.115, it was a batch sparge, I ran some 1.040ish wort into a 10 gallon kettle I have, then boiled it hard until it was over target, added into the main batch. No small beer on that batch.

That may be the issue.  I wonder if Beersmith compensates for the loss in efficiency of a big beer.  Maybe it is a setting I can manipulate.
Steve
All Hands Brewing
BJCP #D1667

Offline Stevie

  • Official Poobah of No Life.
  • *
  • Posts: 6858
    • View Profile
Re: Big beer OG Misses
« Reply #6 on: August 06, 2015, 02:00:20 AM »
It is something you will learn as you brew on your system. I get about 60-63% on beers 10% and over. One thing you can do is sparge more and boil for 120 minutes. I do this frequently and it helps a bit.

The best choice in my opinion is to partigyle.

Offline yso191

  • Senior Brewmaster
  • ******
  • Posts: 1785
  • Yakima, WA
    • View Profile
Re: Big beer OG Misses
« Reply #7 on: August 06, 2015, 02:33:10 AM »
Yep, I just learned something.  I plugged 62% in the efficiency field and boom - 1.076 predicted.  Now I know.  I've been keeping it at 75%.

Thanks all!
Steve
All Hands Brewing
BJCP #D1667

Offline a10t2

  • Official Poobah of No Life.
  • *
  • Posts: 4450
  • Ask me why I don't like Chico!
    • View Profile
    • SeanTerrill.com
Re: Big beer OG Misses
« Reply #8 on: August 06, 2015, 02:48:20 AM »
If you're batch-sparging, use this: http://seanterrill.com/batchsparge
Sent from my Microsoft Bob

Beer is like porn. You can buy it, but it's more fun to make your own.
Refractometer Calculator | Batch Sparging Calculator | Two Mile Brewing Co.

Offline yso191

  • Senior Brewmaster
  • ******
  • Posts: 1785
  • Yakima, WA
    • View Profile
Re: Big beer OG Misses
« Reply #9 on: August 06, 2015, 02:58:41 AM »
I feel like whacking myself on the forehead.  This is something I should have known.
Steve
All Hands Brewing
BJCP #D1667