Beersmith IBU accuracy

[LagerLover24]

I was plugging some of Jamil's recipies into beersmith, and the IBU's don't match up. The settings are 6 gallons batch, 70% efficiency, and Rager for IBU. His Myburger recipe says 36 IBU, but I come up with 27. Tried it with two others, and both were off. Am I doing something wrong?

 

[Revvy]

What ibu scale is his made with? Also do you have the batch volumes the same as his? Aren't his recipes usually 5.5 gallons or 6? Not five, which is the default for beersmith.

 

[LagerLover24]

Book says Rager, and "6 gallons at the end of the boil." I set beersmith at 6 gallons.

 

[Malticulous]

Beersmith is just as good as whatever JZ used. You have to get used to whatever it is you want to use and stick with it so you can predict what you get from your own process. JZ has said as much before on this forum. Keep in mind it's only a prediction, subtle changes in process can have big effects on the outcome.

 

[dcp27]

the boil size is probably different