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-   -   Very Inconsistent all grain efficiency (http://www.homebrewtalk.com/f36/very-inconsistent-all-grain-efficiency-368467/)

MrMista 11-17-2012 10:39 PM

Very Inconsistent all grain efficiency
 
Hello everyone. I have had some very inconsistent with my all grain setup. I batch sparge, usually with a single infusion. I will mash in at 164 degrees so that my grainbed will hit 150 degrees. I then mash for 60 minutes, and stir up the mash at the 30 minute mark. I then get the initial runoff and subtract that amount from my desired boil volume. I then heat up that much water to 185 degrees, add it to the mash tun, stir it up, let it sit for 10 minutes and then run it off into my kettle. During both runoffs I always vorlouf.

I have not gotten consistent results and have no idea why. These are the recipes and expected/calculated OGs.

1: AHS Blue Moon Clone: Expected- 1.053 Got- 1.044
2: AHS Oatmeal Stout: Expected- 1.053 Got- 1.060
3. AHS Our Holiday Special Ale: Expected 1.050 Got- 1.050
4. AHS American Red ALe: Expected- 1.053 Got- 1.044

Does anyone have any ideas for why I have such wild variation? Once I hit it dead on, twice I was way under, and once I was way over.

tgmartin000 11-17-2012 11:18 PM

Do you pay attention to pH? Looks like the darker beers had a better effeciency ...

wolfman_48442 11-18-2012 12:38 AM

Are these all pre-measured and milled kits?
If so, I wonder if grain weight and/or crush are not very consistent.

MrMista 11-20-2012 05:58 AM

Hello, thank you for the help. Sorry for the late reply.

These are all pre-measured kits but the grains were freshly milled the day before. I get them from Austin Homebrew Supply and the crush looks pretty good to me. The Holiday Ale and the Red Ale were milled on the same day and an employee told me that the rollers had just been changed. So those two should at least be consistent.

Below are the grain bills for each recipe. The Oatmeal Stout was obviously dark, but the red ale and the holiday ale were not especially light. I live in Austin, but I am not really sure how Austin's PH levels affect all grain brewing.

1: AHS Blue Moon Clone: Expected- 1.053 Got- 1.044
3lb white wheat
1 lb flaked oats
1/2 lb flaked wheat
5 1/2 lb belgian pilsner malt

2: AHS Oatmeal Stout: Expected- 1.053 Got- 1.060
9 1/2 lb maris otter malt
1/2 lb chocolate malt
1/2 lb crystal 60L malt
1/4 lb black patent malt
1/4 lb black roasted barley
1 lb flaked oats

3. AHS Our Holiday Special Ale: Expected 1.050 Got- 1.050
3/4 lb crystal 60L malt
2oz Chocolate Malt
9 1/2 lb 2-row malt

4. AHS American Red ALe: Expected- 1.053 Got- 1.044
3lb Munich malt
6lb 2-row malt
4oz Special B malt
8 oz Cara Munich malt


Does it seem like PH could be the issue?

Odin_Brews 11-20-2012 07:40 AM

Do you have the same issue and variability with pre-boil OG. Just wondering if evaporation rates are varying, boiling off more or less wort leading to higher or lower OG.

Edit: Looking closer at your recipes Id say something is amiss. the stout and holiday ale have about 10-12 lb of malt, the other guys with low efficiency have about half that amount. Not as much grain = lower og, or are those half batches?

MrMista 11-21-2012 05:28 AM

My evaporation rates are pretty insane. If I have 7 gallons preboil (60 minute boil), by the time I get everything into the fermenter I will have just under 5 gallons. I do have some slight variation in evaporation, but I am not sure if += .3 gallons should give such big swings.

I had some typos in my original post that I have now corrected, thats what I get for not proofreading!

Begin2Brew 11-21-2012 11:12 AM

Looking at your grain bills, I would expect the OG you hit. The weights range a few pounds but only .003 in gravity points. Did you run this through any brewing software?

Jbt 11-21-2012 11:48 AM

I agree your eff looks about the same for each. Different grain bill sizes. But I did not run them thru software.

ajf 11-21-2012 01:50 PM

I ran each of those grain bills through ProMash and adjusted the efficiency settings to obtain the expected gravity and your actual gravity assuming a 5 gallon batch.
Here are the results:
  1. Efficiency of 71% would give 1.053. Efficiency of 59% would give 1.044
  2. Efficiency of 60% would give 1.053. Efficiency of 68% would give 1.060
  3. Efficiency of 68% gives 1.050
  4. Efficiency of 75% would give 1.053. Efficiency of 63% would give 1.044
It seems that your efficiencies (which vary over 9 percentage points) are more consistent than the batches (which vary over 15 percentage points).


Are you sure that the recipies are all for the same batch size - especially recipe 2?


For batch 1 (where you got 59% efficiency) there is a substantial amount of wheat. As wheat grains ares smaller than barley, they may need to be milled with a smaller gap than barley (or milled twice). This could possibly explain why you only got 59% efficiency on batch 1.


Batches 2 and 3, you got 68% efficiency, but I cannot see any reason why reason why your efficiency dropped to 63% on batch 4.


-a.

tgmartin000 11-21-2012 05:11 PM

How's your mash in process? How about your runoff rate? Do you really stir the sparge? What's your sparge like?

On edit I reread the op. How about sparge temp? Other than that, I'd try to look into your water, see if it isn't a pH issue.


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