Hop % to oz using BeerSmith

Hi guys. Dumb question. Does BeerSmith have a way to convert hops by percent like the grain percent option? The recipes in Mitch Steele's IPA book has hops listed at a percent. Or how do I figure out %?

Example:

Start of boil use 23.3% of 17.7%aa CTZ hops

So how many oz would 23.3% be for a 5 gallon batch?


Thanks in advance.

Keith

I don't know about the software, but this is an algebra problem.

Take the % x Total x utilization x AA% for each addition. When you add all those together, they equal the total IBU. Then you solve for "Total". You'll need a utilization chart based on boil minutes and gravity.

Alternatively, if you don't like algebra and charts..... plug in 1 oz for the bittering addition and scale the rest based on the percentages. eg if the bittering addition is 23% and the 15 minute addition is 40%, 1 oz bittering means 1 x 40%/23% = 1.74 oz at 15 minutes. Plug all those in to your program to calculate IBU. Whatever % your IBU is off, multiple all the additions by that amount. eg. if you are 10% low, the 1 oz bittering becomes 1.1 oz and the 1.74 @ 15 minutes become 1.91 oz.

BTW - what recipe are you trying?

You could do the algebra approach that bill suggests. Or, you can plug in everything using your recipe's %aa values and record your IBU values. Then, correct the %aa to actual, and use the adjust IBU feature in Beersmith, which will adjust the hop amounts upward or downward as necessary.

Thanks guys. Did I mention I hate math? lol

The example was from Fat Heads Headhunter IPA, but I want to try the Stone 14th Anniversary IPA. The Fathead IBU target is 87. Guess I forgot to mention that as it looks like it is a big contributing factor.

The percentages in Mitch's book are the percentage of the total hop weight, not the percentage of contribution to the total IBU.