Basically a Porter Math Question

[MindenMan]

Jamil's Who's Your Taddy Porter recipe has me stumped.
http://brubrog.wordpress.com/2012/01/12/whos-your-taddy-porter-jamils-recipe/
Using Qbrew, I get an O.G. of 1.057, and his recipe says 1.052.
I guess why I am stumped is, why is my predicted O.G. higher than his recipe?
I would think his efficiency would be higher than mine. Any ideas?

 

[Heavywalker]

This is a complete guess, but there are only a few options.

1. Your efficiency is higher than his.
2. He posted the recipe at a lower efficiency to be more in line with what the average homebrewer is getting.

 

[WayFrae]

It looks like the recipe is calculated at 70% efficiency. If you get a higher efficiency than that, either adjust the recipe to fit your efficiency or just brew as is and have a slightly higher ABV.

 

[JustLooking]

You should enter grains into software as a percentage of the whole, not an actual amount. Base the amounts on how much grain you'll need to get the predicted OG using your efficiency.