I'm trying to convert a simple hop schedule to hit the desired IBU mark. The hops my LHBS carries are 4.5% and the recipe I am going from used 5.0%.
The recipe adds 1.0 oz Kent Goldings (5.0%) at 60 minutes, for 17.2 IBU. How many ounces of Goldings do I need to add at 60 minutes to hit 17.2 IBU?
Recipe: 1.0oz (5.0%) 60 min = 17.2 IBU
Me: ???oz (4.5%) 60 min = 17.2 IBU