Hello, I am a new time brewer and thought downloading this program would help me with beer recipes. However, I am a little confused on how the BeerSmith2 calculates the IBUs. If I just plug the numbers into the Hop Bitterness Tool using Tinseth I get one reading. For example.
Northern Brewer Hops 1 oz x 60 mins = 31.6 IBU
Amarillo Hops 1 oz x 5 mins = 6.8 IBU
Amarillo Hops 2 oz x 0 mins = 0 IBU
If I put the same hop profile in the new recipe program I get different numbers. For example.
Northern Brewer Hops 1 oz x 60 mins = 50.5 IBU
Amarillo Hops 1 oz x 5 mins = 10.9 IBU
Amarillo Hops 2 oz x 0 mins = 0 IBU
Then as I add grains to the IBUs decrease until it comes out to 28.1 by the end of the recipe. I am actually following a recipe that was calculated to around 41 IBUs.
I don't understand why there is a difference. I am looking at an extract recipe using a 3.1 gal boil to achieve a final 5.0 gal output.
I think I get the formula IBU - AAU x U x 75/V.
So is the Hop Bitterness Tool using a set utilization rate and the recipe calculation is actually based on the boil gravity?
Not trying to make this harder than it needs to be just trying to understand how the program figures out the IBUs.
Thanks
Northern Brewer Hops 1 oz x 60 mins = 31.6 IBU
Amarillo Hops 1 oz x 5 mins = 6.8 IBU
Amarillo Hops 2 oz x 0 mins = 0 IBU
If I put the same hop profile in the new recipe program I get different numbers. For example.
Northern Brewer Hops 1 oz x 60 mins = 50.5 IBU
Amarillo Hops 1 oz x 5 mins = 10.9 IBU
Amarillo Hops 2 oz x 0 mins = 0 IBU
Then as I add grains to the IBUs decrease until it comes out to 28.1 by the end of the recipe. I am actually following a recipe that was calculated to around 41 IBUs.
I don't understand why there is a difference. I am looking at an extract recipe using a 3.1 gal boil to achieve a final 5.0 gal output.
I think I get the formula IBU - AAU x U x 75/V.
So is the Hop Bitterness Tool using a set utilization rate and the recipe calculation is actually based on the boil gravity?
Not trying to make this harder than it needs to be just trying to understand how the program figures out the IBUs.
Thanks