What is my brewhouse efficiency?

[h22lude]

I've searched for calculators and formulas. I always come out with different numbers. BeerSmith says it was 68% but another calculator I found said it was 77%.

Grain bill:
5lb Marris Otter
3lb Vienna
2lb Munich
.5lb Crystal 20L
.5lb Crystal 60L

Mashed in with 3.4 gallons
Mashed out with 1.9 gallons
Sparged with 3.9 gallons
Pre boil volume was about 7.6 gallons (which was about .2 gallons shy of water BeerSmith calculated)
Pre boil gravity was 1.042 (which was only 1 point higher from BeerSmith)
Post boil volume was 5.5 gallons (I only took 5.25 gallons into my primary)
Post boil gravity was 1.053 (which was 5 points lower than what BeerSmith had using 75% efficiency).

BeerSmith calculated my efficiency using this brew as 68%. I'm just curious why this is so far off from the other calculator I used which told me it was 77%. I'm not disappointed with 68% (though I would rather have 77% lol) but I just want to make sure I use the correct number so my brew sheet comes out with the correct water and gravity figures.

 

[bob1852]

I calculate a post boil efficiency at ~74%.

I don't use BeerSmith, so can't really help you out with that, but here's my math:

5lb Marris Otter (185 PPG)
3lb Vienna (105 PPG)
2lb Munich (70 PPG)
.5lb Crystal 20L (17 PPG)
.5lb Crystal 60L (17.5 PPG)

total PPG = 394.5

394.5 / 5.5g = 72 possible points

1.053 / 1.072 = 53/72 = ~74%

 

[dhoyt714]

I have noticed if you don't the exact grain that you are using in the calc. it can make your efficiency vary a few points, and maybe that is why its off a little?

Go Pats!

 

[h22lude]

I have noticed if you don't the exact grain that you are using in the calc. it can make your efficiency vary a few points, and maybe that is why its off a little?

Go Pats!

BeerSmith and the calculator I found both used the exact grains I used so it should be accurate.