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Mash Efficiency

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mlager:
I'm using Beer Smith and I'm trying to figure out my efficiency... I set my brewhouse efficiency to 75%. I was shooting for a 1.051 beer. My pre-boil gravity was 1.046 and I ended up with an OG of 1.050. So I plugged these numbers into Beer Smith. It gives me 3 percentages:

1) Actual efficiency: 74.03%
2) Efficiency into boilder: 85.13%
3) Efficiency as calculated from actual volume: 74.03%

Which one is related to the "Brewhouse efficiency"? Trying to figure out if I'm on target with 75% or if I'm higher. My future recipes should be adjusted according to which reading I use I guess.

Hokerer:
As long as you're using your post-boil volume as the actual volume you enter (after clicking the "Brewhouse Efficiency" button), then number 3) is your brewhouse efficiency.

mlager:
Yes the actual volume is the post boil volume. I went 7.5 gallons into the kettle, boiled off 1.5, and put 6 gals into the carboy.

bluesman:
As long as your batch volume has been met then "Efficiency as calculated from actual volume: 74.03%" is your BE.

This calculation is only correct if your volumes are correct.

tygo:

--- Quote from: bluesman on January 15, 2011, 01:30:30 AM ---This calculation is only correct if your volumes are correct.

--- End quote ---

And I don't think they are.

Something doesn't seem right with your measurements.

If your pre-boil gravity was 1.046 and volume was 7.5 gallons then you had:  46 x 7.5 = 345 total gravity points.

If you boiled off 1.5 gallons and ended up with 6 gallons of wort into the fermenter the OG should have been:  345/6 = 57.5 or ~ 1.058.

How sure are you about your volume measurements?  If you really had 7.5 gallons at 1.046 then at 1.050 then you still had about 7 gallons of wort after the boil.  For a 60 minute boil that's only a boil off rate of 6.67% per hour which doesn't seem likely.

I'm going to guess that your volume measurements are off and your SG readings are accurate.   Also, are you accounting for the wort lost to trub and hops in the kettle?  Any wort left behind in the kettle is also leaving sugars behind.