Author Topic: Mash Efficiency unusually high  (Read 11453 times)

Offline bugac

  • BeerSmith Apprentice Brewer
  • **
  • Posts: 10
  • BeerSmith 2 Rocks!
Mash Efficiency unusually high
« on: November 18, 2013, 10:10:52 AM »
Ok, this is my 2nd batch where my mash efficiency has come in, in the 90's.

I use beersmith to calculate my recipes.

I've brewed 5 batches this year. My mash efficiencies have been 83.3, 83.1, 89, 97, and 92.6. I've used 5.2 stabilizer in my last 4. However, my second batch this year (83.1), 5.2 wasn't thrown in until 30 minutes into my mash (forgot about it).

My second to last brew, an oatmeal stout, had a very high mash efficiency. My mash efficiency, according to beersmith, came in at 97%. I had a typical 60 minute mash and 60 minute boil. My brewhouse efficiency came out to 82.8% and my total efficiency was 82.5%. When measuring my OG, i came in 10 points higher than expected. My FG also finished 10 points higher. The beer tastes great, but the higher than expected gravity and efficiency is throwing off my recipe planning.

My last brew, a christmas IPA, was somewhat new to me. First, i mashed for 70 minutes for the first time, and conducted a 90 minute boil (first time). My mash efficiency came out to 92.6%. However, i planned for a 5.5 gallon batch, but only came out with 4.5 gallons @ 97% eff. So i added 1 gallon of water to the fermenter and my efficiency went to 92.7. My OG, like my last batch, is 10 points higher at 1.078 (instead of 1.068). If history stands corrected, my FG will be 10 points high as well at 1.022, which is not what i want.

My hydrometer is calibrated correctly, and I have not had anything go wrong on my brewday. The only thing i can think of that might be going on, is the 5.2 stabilizer is causing my efficiency to be higher than estimated.

Below is my recipe and my results from Brew Day Saturday.

11 lbs. 4 oz Maris Otter
1 lb 7 oz. Caramel Malt 60L
14 oz. Caraamber
9 oz. Rye

Pre-boil volume = 7.2 gallons
Pre-Boil OG = 1.072

Post-Boil Volume = 4.5 gallons
Post-boil OG = 1.088

Added 1 gallon of water to fermenter
5.5 gallons at 1.078

My original target OG, according to beersmith was 1.068

I use a 9.5 gallon brewpot, a 10 gallon igloo mash tun, and a 10 gallon igloo sparge tank. Fly Sparge

My brewing techniques, grain supplier, and brew water has not changed.

Offline MaltLicker

  • Global Moderator
  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 2004
    • Blue Ribbon Brews
Re: Mash Efficiency unusually high
« Reply #1 on: November 18, 2013, 10:42:02 AM »
11 lbs. 4 oz Maris Otter
1 lb 7 oz. Caramel Malt 60L
14 oz. Caraamber
9 oz. Rye

Pre-boil volume = 7.2 gallons
Pre-Boil OG = 1.072

Post-Boil Volume = 4.5 gallons
Post-boil OG = 1.088

Added 1 gallon of water to fermenter
5.5 gallons at 1.078

My original target OG, according to beersmith was 1.068


One hunch is I think you're boiling off much more than you think.  If 1.072 and 1.088 are Actuals, then you boiled off 16 points (after knowing you were already high on OG).   And came up a gallon short on volume, indicating a too-aggressive boil. 

I would break it down into Estimates and Actual Measured Results, and compare Pre-Boil numbers and then compare Post-Boil numbers.   And look at volumes closely.     16 points on the base of 72 is 22% boil-off.   


As you're figuring it out, one tactic to get the beer you want would be to monitor the gravity and adjust on the fly.  Here, you could have stop collecting wort and immediately diluted with water to get the Forecasted Pre-Boil SG which was likely below 1.060 if the final OG target was 1.068.   That would help keep hop utilization closer to expected as well, compared with diluting after the boil. 

It seems your EE% is higher than you've told BS2, so that's easily fixed next time, and BS2 will tell you to use less grain accordingly. 

Measure and monitor SG at all stages of the boil to get an understanding of your evaporation rate. 


I do wish BS2 had an option to track evaporation rate more by the change in SG than boil-off amount or percentage, which is harder to measure during a 212F splashy boil scenario.   



Offline brewfun

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 2305
  • Malt dust is just alcohol's glitter
Re: Mash Efficiency unusually high
« Reply #2 on: November 18, 2013, 11:49:05 AM »
The numbers don't look right to me. Something is missing. Are theses all in-kettle measurements? Is the pre-boil volume taken at about 200F or higher? Is the post boil volume after chilling? BeerSmith's math anticipates that the pre-boil volume is hot (it includes the 4% expansion) and the post boil volume is chilled.

Efficiencies in the mid 90's isn't unheard of. The boil off rate is enormous at around 36%.

But only one of those two measurement points (pre or post boil) is accurate. I'm going with the post boil number before adding water, because it represents the most well mixed part of the process. Let's start by summing up the sugar as OG x Vol / Wght.

Preboil total is 525.6, for a pppg of 34.75.
Postboil pppg is 396 for a pppg of 26.18

The totals should match, but don't in your case. Both of those numbers are in the realm of possibility, but the pre boil number represents about 92% efficiency, while the post boil is about 70%. I used rough, rounded numbers of 38 points as 100% extraction. Actual potential could make these a bit higher, but this is good for comparison. ...If both are in-kettle, they can't both be correct.

To compound this further, the additional gallon of water should have yielded a 1.072, which is much closer to your anticipated 1.068.

These variations could be caused by something as simple as not mixing the wort enough before taking a sample. If you're gentle enough, first runnings can sit on the bottom of the kettle, separating like a big 'ol black and tan. Stick an eye dropper or wine thief down there for a sample and it is much higher than the mixed average will be.
Beer Appreciation is the space between pints.

Offline bugac

  • BeerSmith Apprentice Brewer
  • **
  • Posts: 10
  • BeerSmith 2 Rocks!
Re: Mash Efficiency unusually high
« Reply #3 on: November 18, 2013, 12:19:48 PM »
Let me rephrase what i'm trying to convey, i don't think i'm giving all the information.

I mashed for 70 minutes. After recirculating and adding my running into the brew pot, i collected 7.1 gallons of wort at an OG of 1.068 (adjusted for temperature of 135). I took the reading using my thief in the brewpot.

I then, conducted a 90 minute boil. It did start to get a bit windy towards the end of the boil, and i was constantly knocking down my heat to reduce such a vigorous boil.

Post-boil, i whirlpooled my hops for 10 minutes, then cooled for about 15 minutes, then added to my primary carboy. I only had 4.5 gallons of wort collected. So, i checked my gravity again, with the wort temperature at about 80 degrees, and my gravity was at 1.0926. I adjusted because my hydrometer is 2 points off, and so i was at 1.09 OG. I then added 1 gallon of water to my carboy to get my volume to 5.5 gallons. I then sealed the top and shook the hell out of the fermenter. I waited about 5-7 minutes and took another reading. My OG was then at 1.078. I waited another 5 and rechecked, and confirmed my gravity to be 1.078

Also, based on my grain bill, i come up with a Potential points of 72.9

Grain        Potential Points   Grain Pts   Weight (LBS)
Maris Otter      56.7                  36    11.33
Caramel Malt      7.5                  34      1.583
Caraamber      5.7                  35     1.167
Rye                      3                 29     0.75
 TOTAL                72.9                134    14.83

Which according to this website  http://www.brewersfriend.com/brewhouse-efficiency/

My Mash Efficiency was 87.38%, not 92%.
My brewhouse efficiency was 75.42%
and my adjusted brewhouse efficiency with the added 1 gallon of water is 77.64%

I still don't understand how beersmith came up with a 92% efficiency rate.

Offline Oginme

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 3156
  • Goats, guitars, and a home brew; Life is good!
    • Longvu LaManchas
Re: Mash Efficiency unusually high
« Reply #4 on: November 18, 2013, 12:58:43 PM »
For the purposes of mash efficiency, the only numbers that are important are the gallons of wort collected from the mash and the specific gravity.  Using the formulation you provided:

M.O.       11.33 lbs    36 pppg   407.9 grav pts
caramel    1.583 lbs  34 pppg    53.8 grav pts
C-amber   1.168 lbs  35 pppg    40.9 grav pts
Rye           0.75 lbs    39 pppg    21.8 grav pts

total gravity points potential:  524.3
Gallons of wort:                           7.1
maximum gravity attainable      1.0738
Actual attained:                         1.068
Mash efficiency:                           92%

As with Brewfun, I think the numbers beyond this are confusing.  During the boil, you should be concentrating gravity points, and not losing them.  The disparity here makes me think that some of the volume measurements are possibly off.  The amount of losses in your kettle may help to make it balance with your final collected numbers.
                       
Recycle your grains, feed them to a goat!

Offline bugac

  • BeerSmith Apprentice Brewer
  • **
  • Posts: 10
  • BeerSmith 2 Rocks!
Re: Mash Efficiency unusually high
« Reply #5 on: November 18, 2013, 01:02:30 PM »
Quote
For the purposes of mash efficiency, the only numbers that are important are the gallons of wort collected from the mash and the specific gravity. 

Correct. I'm simultaneously posting in another local forum for information as well. Getting sidetracked.

But i too came up with 92% in beersmith.

Is it possible that my efficiency is this high? I want it to be in the low 80's. I did 2 brews earlier this year and both dialed right in at 83%. What could be the difference maker. Is the 5.2 ph stabilizer an issue maybe?

Offline Oginme

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 3156
  • Goats, guitars, and a home brew; Life is good!
    • Longvu LaManchas
Re: Mash Efficiency unusually high
« Reply #6 on: November 18, 2013, 02:37:23 PM »
92% is not unheard of.  My process is consistently around 85% mash efficiency.  Difference can be in some of the little things:  allowing the sparge to run to a lower gravity, slight change in grind, conditioning of grain before grinding, fluctuations in the temperature of the sparge water, drainage rate if you are doing a fly sparge, etc. 

I have found that I get slightly higher efficiencies when I am doing a session beer versus a higher gravity brew.  It's nothing I plan on and when I get enough data points I may try to model it. 

I have never tried the pH 5.2, so I could not comment on the effect it might be having.
Recycle your grains, feed them to a goat!

Offline MaltLicker

  • Global Moderator
  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 2004
    • Blue Ribbon Brews
Re: Mash Efficiency unusually high
« Reply #7 on: November 18, 2013, 03:32:19 PM »
Is it possible that my efficiency is this high? I want it to be in the low 80's. I did 2 brews earlier this year and both dialed right in at 83%. What could be the difference maker. Is the 5.2 ph stabilizer an issue maybe?

I agree that something seems to be unaccounted for, and I personally think 5.2 may you gain a few points, depending on your starting chemistry point, but unlikely to increase EE% by 10%. 

Ten percent jumps in EE% are most likely explained by volume differences, and the lack of a full gallon post-boil would be the aggressive boil. 

Offline brewfun

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 2305
  • Malt dust is just alcohol's glitter
Re: Mash Efficiency unusually high
« Reply #8 on: November 18, 2013, 06:10:36 PM »
I'm seeing that the batch volume was in the fermenter.

How much was left in the kettle? Was this in your equipment profile as "Loss to Trub and Chiller"? If so, this artificially inflates your mash efficiency. If it's there, zero it out and add it to the batch volume, then add the trub loss in "Fermenter Loss."  Not elegant, but it'll correct your numbers.

With the level of precision you're asking, it'd be good to have a current malt batch spec on all of your base malts. For Maris Otter, you have to ask, "Which one?" because they can all have differing yields.

I use Thomas Fawcett and the current batch* specs are:
Yield: 82%
Potential: 1.038
Color: 2.5 SRM
Moisture: 3.1%
Diastatic: 65 Lintner
Protein: 8%

*Base Malt batches are HUGE and just one or two can cover the US for 3 months or more.

Muntons is another popular one. I can only find their target specs:
Yield: 80-82%
Potential: 1.037-1.038
Color: 2.5-3 SRM
Moisture: 3-3.5%
Diastatic: 50-70 Lintner
Protein: 8-12%

Crisp comes in with the softest batch specs, currently:
Yield: 78.9%
Potential: 1.036
Color: 3.6 SRM
Moisture: 3-3.5%
Diastatic: 52 Lintner
Protein: 10.9%

Beer Appreciation is the space between pints.

Offline MaltLicker

  • Global Moderator
  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 2004
    • Blue Ribbon Brews
Re: Mash Efficiency unusually high
« Reply #9 on: November 19, 2013, 04:15:48 PM »
brewfun

How much difficulty does that level of variance cause a pro brewer?   79 to 82% yield across a 200 barrel batch? 

Offline Maine Homebrewer

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 1371
Re: Mash Efficiency unusually high
« Reply #10 on: November 19, 2013, 05:58:33 PM »
I used this url http://www.brewersfriend.com/brewhouse-efficiency/ that I found at the top of a google search for "homebrew efficiency calculator."

Inputted 5.5g @ 1.078 O.G., 11.25# Maris Otter, 1.25# Caramel 60L, .8# CaraAmber, .6# rye, and the following was the result:

Quote
Gravity at 100% Efficiency: 1.096 - max
Gravity at 75% Efficiency:  1.072
* Efficiency: 81.17%

You've got a lot of extraneous data. I like the KISS rule myself (Keep It Simple S-word). Can't stand the band, but I like the rule. My guess is that you're over-complicating things with too much data.

Speaking of rockers in costumes, have you seen GWAR play Kansas' "Carry on my Wayward Son"? If not, it's worth a youtube. I laughed until I choked, then I choked some more.
« Last Edit: November 19, 2013, 06:11:00 PM by Maine Homebrewer »
"To alcohol! The cause of - and solution to - all of life's problems!" -Homer Simpson

Offline brewfun

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 2305
  • Malt dust is just alcohol's glitter
Re: Mash Efficiency unusually high
« Reply #11 on: November 19, 2013, 07:26:07 PM »
brewfun

How much difficulty does that level of variance cause a pro brewer?   79 to 82% yield across a 200 barrel batch?

A lot. Even at 15-20 bbl (not too many craft brewers making 200 bbl batches). It can cost several barrels of beer, or to put it another way; a lot of profit.

Which is why malt analysis is so important. Not so much on specialty malts, but definitely on the base malts. Busy breweries take delivery samples and do their own analysis for extract, at least.
Beer Appreciation is the space between pints.

Offline RiverBrewer

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 208
  • BeerSmith 3+ Rocks!
Re: Mash Efficiency unusually high
« Reply #12 on: November 24, 2013, 08:34:41 PM »
Yes, I have to agree that something is wrong with the numbers. A 7.2 gallon PreBV with a PostBV of 4.5 gallons would show you boiled off 2.7 gallons in 90 minutes or 1.8 gallons/hr. The resulting boil off/hr. would be 25%/ hr. You must be boiling in the exhaust of a jet aircraft engine???
Enjoy good beer daily.....Hell is a dry town!
Retired with an Ultra Limited ride!

 

modification